Knowledge of the population on the influence of diet on renal lithiasis

doi:10.21203/rs.3.rs-2023270/v1

Kidney stones is a very prevalent disease, whose morbidity is associated with the recurrence of stone formation. Food plays an important role in the prevention and treatment of the disease, but this impact is still not widespread. Objective: The present study aims to evaluate the knowledge of the general population and of individuals with nephrolithiasis regarding the formation of kidney stones and the dietary measures recommended for their prevention. Methods: This is a descriptive, cross-sectional study, with a convenient sample. Data were collected using an online questionnaire containing 39 questions [sociodemographic data (8), health data (14), and dietary treatment knowledge (17)], shared on social media. Results: The questionnaire was answered by 283 participants [76.1% women; median age 34.5 (28-75.41) years], 61. 5% reporting being lithiasic. The lythiasic group had more comorbidities than the non-lythiasic one. Most of the participants (85.9%) believed that diet could prevent the formation of kidney stones, with higher frequency in the non-lythiasic group (93.6% vs lythiasics81%, p=0.003).Lithiasics in comparison with non-lythiasics presented lower frequency of correct answers for the items "increased fluid intake" (87.9% vs 95.4%, p=0.034) and "regular consumption of fruits, vegetables and vegetables" (47.7% vs 60.6%, p=0.035), the factors that decrease stone formation; and "milk chocolate being the most indicated for individuals with oxalate-based stones" (5.7% vs 13.8%, p=0.021). However, lithiasics had a higher frequency of correct answers about "low calcium intake increases stone formation" (29.9% vs non-lithiasics: 24.8%, p=0.018). Conclusion: the present study shows that there are gaps in knowledge about dietary advice in patients with renal lithiasis, which is even more worrying about the few differences when compared to non-lithiasic individuals.

Diet

Diet therapy Kidney Calculi

Knowledge

Nephrolithiasis

Renal lithiasis affects 5 to 15% of the world population and its recurrence rate exceeds 50%.^1–2 National data showed an increase from 43,176 to 69,309 admissions to the SUS (Unified Health System) related to renal lithiasis between 1996 and 2010. According to DATASUS data, 69,039 hospitalizations related to renal lithiasis were performed, corresponding to 0.61% of the total number of hospitalizations in the SUS in 2010. The average cost of hospitalizations was R$ 423.42, with a total expenditure of R$ 29,232,682.56 in the year.³

Studies show that this increase in the incidence of the disease over the years accompanies the increase in obesity rates, sedentary lifestyle and sodium consumption by the population, indicating a relationship between renal lithiasis and the quality of food and lifestyle. Thus, despite the importance of genetic factors, environmental factors have been increasingly relevant in the pathogenesis ofrenal lithiasis.^4–8

Kidney stones are formed from the imbalance in the urine between promoting factors (oxalate, calcium, uric acid and phosphorus) and inhibitors (citrate, potassium and magnesium) of crystallization, under a certain pH, and influenced by low urinary volume.5,9 ,10 Hypercalciuria, hyperoxaluria, hyperuricosuria, and hypocitraturia are the most commonly observed metabolic disorders in individuals with kidney stones. 11 About 80% of stones are composed of calcium salts (eg calcium oxalate and calcium phosphate), 10% uric acid, 9% struvite and 1% cystine.5,9 Many of these urinary factors are influenced by diet., thus nutritional management is essential in preventing recurrence of kidney stones.⁹

Nutritional recommendations for patients with renal lithiasis are diverse and depend on the urinary metabolic profile, type of stone formed and nutritional status of patients. ¹² The increase in fluid intake is essential and considered the main independent factor for protection against new kidney stones.10 Other general guidelines include control in sodium intake, protein (normoproteic) and adequate calcium intake. Among the specific guidelines, there is a reduction in oxalate intake (for hyperoxaluria), uric acid (for hyperuricosuria) and an increase in citrate intake (for hypocitraturia).¹²⁻¹5 Dietary adjustments also help to modulate urinary pH; Feeding with a higher proportion of foods rich in magnesium, potassium and calcium and lower in phosphate and proteins has the potential to alkalize the urine. ¹⁶ Studies of dietary patterns show that a diet rich in sodium, animal proteins, drinks sweetened with sugar and/or fructose and low in calcium can favor the formation of kidney stones; while a more balanced eating pattern, characterized by adequate consumption of fruits and vegetables, has been shown to be protective.¹⁰It is known that the latter foods are sources of factors that inhibit crystallization, such as citrate, potassium and magnesium, in addition to providing lower acid load to the body, modulating urinary pH.^16–19

In view of the above, it is clear that food can play a very important role in the prevention and treatment of renal lithiasis. However, it is still a little known knowledge, both among health professionals and the general population.^20–21 In this context, the present study aims to evaluate the knowledge of the general population and of lithiasisic individuals about the formation of kidney stones and the dietary measures recommended for their prevention.

This is a descriptive, cross-sectional study with a convenience sample. The inclusion criteria were: individuals over 18 years of age, of both sexes, with access to electronic equipment connected to the internet network. Individuals who did not answer all the questions in the questionnaire were excluded. This project was approved by the Ethics Committee of Centro Universitário São Camilo (05.025-010) and all participants signed the Free and Informed Consent Form (ICF).

Protocol

The protocol included the application of an electronic questionnaire, divided into two parts: 1) sociodemographic and clinical data, 2) questionnaire on knowledge about food andrenal lithiasis. The invitation to participate in the research was carried out through dissemination on social networks (Facebook®, Instagram®and whatsapp®), including groups and communities on kidney stones. Data were collected from October 2020 to November 2020, using an electronic form (google forms).

knowledge questionnaire

The questionnaire applied was produced based on the researchers' knowledge on the topic “food and kidney stones”; contained 39 questions, 8 on sociodemographic data, 14 on health, and 17 on diet and kidney stones.

Statistical analysis

The distribution of continuous variables was assessed using the Kolmogorov-Smirnov test. Data were presented as absolute and relative frequency, mean and standard deviation or median and interquartile range, according to the nature and distribution of the variables. Differences between groups were detected from the chi-square test, student's t test or Mann-Whitney test, as appropriate. Correlations between continuous variables were obtained by Pearson's or Spearman's correlation tests, as appropriate. Analyzes were performed using SPSS version 20 (IBM, Chicago) and p < 0.05 was established as the limit of statistical significance.

The questionnaire was answered by 283 people and the majority reported being litiasic (61.5%). The sociodemographic and clinical characteristics of the participants and the groups (lithiasic and non-lithiasic) are described in table 1. The lithiasic group was composed mostly of women (81%) and individuals with a lower level of education; 57.5% did not have higher education. The median body mass index (BMI) was higher in the lithiasic population (27.5 kg/m²), as was the prevalence of comorbidities such as arterial hypertension (19%) and hyperuricemia/gout (9.2%).

Among the lithiasis patients, the year of discovery of kidney stones was 2015 (2008–2019). Most of these individuals (59.8%) reported recurrence of kidney stones 3 or more times and 46% had already undergone a surgical procedure to remove the stone. Although the majority of lithiastics know that there are different types of stones (74.1%), most are unaware of the type they present (61.5%). Among those who knew how to report, calcium oxalate calculation was the most cited (32.3%). Regarding food care, 54.3% of the participants said they had never received nutritional guidance, 8.6% were guided by a nutritionist and 41.9% by a doctor or other health professional. Among those who received guidance on nutrition, 46.2% classified their adherence as low or very low, 32.1% as intermediate and only 21, 7% as good or excellent. Of the non-lithiasis patients, the majority (90.8%) reported knowing someone with kidney stones, with the most commonly described relationship being that of colleague/acquaintance (52.3%), that is, non-family members.

Considering all participants, most believe that food could prevent the formation of kidney stones (85.9%), more frequently in non-lithiasis patients (93.6% vs. 81%, p = 0.003). When asked about the degree of knowledge about diet and renal lithiasis, lithiasis patients reported a higher frequency of good/intermediate knowledge than non-lithiasis patients (37.4% vs 21.1%, respectively, p = 0.004). Most participants (59.4%), particularly the non-lithiasis patients (67% vs lithiasic: 54.6%, p = 0.039), reported that the diet for those with kidney stones should not be different from the general food precepts healthy.

Table 2 reveals the knowledge questionnaire alternatives considered correct. The highest percentages of correct answers by the participants in general were for the items “increasing fluid intake can decrease” (90.8%) and “high sodium consumption can increase” (77.4%) the formation of stones. The lowest percentages of correct answers were for the items “milk chocolate is the most suitable for patients with oxalate-based stones” (8.8%) and “high fat consumption has no direct effect on stone formation” (16.6%).

When comparing litiasic and non-lithiasic, the first group had a lower frequency of correct answers for the items “increase in liquids” (87.9% vs non-lithiasic: 95.4%, p = 0.034) and “regular consumption of fruits, vegetables and vegetables” (47.7% vs non-lithiasis: 60.6%, p = 0.035), as factors that reduce stone formation; and “milk chocolate is the most suitable for individuals with oxalate-based stones” (5.7% vs non-lithiasis patients: 13.8%, p = 0.021). However, the lithiasis patients had a higher frequency of correct answers about “low calcium consumption increases the formation of stones” (29.9% vs non-lithiasis patients: 24.8%, p = 0.018).

The present study investigated the knowledge about renal lithiasis and the diet therapy applied to individuals affected and not affected by the disease. About 62% of the participants declared themselves to be litiasic, a frequency higher than that reported in epidemiological studies. ²² It is noteworthy that the frequency found in the present study does not represent the prevalence of renal lithiasis in the population studied, since the questionnaire was also directed to people with renal lithiasis, which may characterize a selection bias.

In general, gaps in knowledge about nutritional guidelines for renal lithiasis were observed. Patients with lithiasis declared themselves to be more knowledgeable about the nutritional guidelines for the treatment and prevention of renal lithiasis than non-lithiasis patients, however, when the guidelines were evaluated separately, the percentage of correct answers for most items did not differ between groups. Furthermore, even in the items in which the lithiasic participants had a higher percentage of correct answers, the difference found between the groups was small. Interestingly, non-lithiasis patients reported more believing in food as a preventive factor for renal lithiasis than those affected by the disease. This result was similar to that exposed by Penninston (2016), in which lithiasic individuals (especially those who underwent calculus removal procedures) believed less in prevention than non-lithiasic individuals. It is possible that this disbelief of patients is related to frustration due to recurrence of stones, which may or may not be linked to inadequate nutritional counseling.²³

Despite the importance of food in the prevention and treatment of lithiasis, more than half of lithiasis patients (54.3%) never received nutritional guidance. This shows that it is still a neglected health problem and little addressed in clinical practice. This fact may contribute to the high rates of stone recurrence found, 59.8% reported recurrence for 3 or more times. The presence of a nutritionist in the multidisciplinary team is not frequent in urology clinics and, therefore, nutritional prevention of new stones through dietary adjustments is not widely practiced. ²³ Among the participants who had already received nutritional guidance, most (41.9%) were not guided by a nutritionist; only 8.6% of the participants received guidance from this professional. Although lithiasic patients can receive general recommendations on food from doctors and other health professionals, diet therapy guided by a nutritionist allows for greater individualization of behaviors, not only for biological characteristics, but also for psychosociocultural aspects, which favors adherence to habit changes. According to Penniston (2016), doctors usually refer patients only when they are motivated to change their diet; however, even those who do not seem motivated should be given the opportunity for a nutritional consultation. Most lithiasics who received previous guidance on dietary care rated their adherence as low or very low (46.2%), reinforcing the importance of individualization in treatment. not only for biological characteristics, but also for psychosociocultural aspects, which favors adherence to changes in habits. According to Penniston (2016), doctors usually refer patients only when they are motivated to change their diet; however, even those who do not seem motivated should be given the opportunity for a nutritional consultation. Most lithiasics who received previous guidance on dietary care rated their adherence as low or very low (46.2%), reinforcing the importance of individualization in treatment. not only for biological characteristics, but also for psychosociocultural aspects, which favors adherence to changes in habits. According to Penniston (2016), doctors usually refer patients only when they are motivated to change their diet; however, even those who do not seem motivated should be given the opportunity for a nutritional consultation. Most lithiasics who received previous guidance on dietary care rated their adherence as low or very low (46.2%), reinforcing the importance of individualization in treatment. however, even those who do not seem motivated should be given the opportunity for a nutritional consultation. Most lithiasics who received previous guidance on dietary care rated their adherence as low or very low (46.2%), reinforcing the importance of individualization in treatment. however, even those who do not seem motivated should be given the opportunity for a nutritional consultation. Most lithiasics who received previous guidance on dietary care rated their adherence as low or very low (46.2%), reinforcing the importance of individualization in treatment.

More and more studies show the relationship between kidney stones and obesity, diabetes, hypertension, metabolic syndrome, coronary artery disease and a sedentary lifestyle.^4–6In fact, some of these characteristics, such as a higher BMI and a higher frequency of hyperuricemia hypertension, were also more prevalent among the group of patients in the present study. One of the mechanisms in which the metabolic syndrome influences the formation of kidney stones involves insulin resistance. ²⁴ Among the mechanisms is the reduction in tubular production of ammonium from L-glutamine, compromising urinary tamponade, which reduces pH and citrate excretion (hypocitraturia) and favors the precipitation of uric acid and oxalate stones. calcium, for example. Therefore, adequate nutritional management of comorbidities can also help in the prevention and treatment of renal lithiasis.

The orientation “increased fluid intake” was the most reported by individuals. Similar results were found in an American study, in which adequate water intake was identified as a protective factor against stone formation by approximately 90% of participants. ²⁵ It was interesting to note that few participants (34.3%) believe that there is scientific evidence on the use of stone break tea to prevent the formation of kidney stones. In the literature there are few clinical trials on the subject and the results show different actions such as ureteral relaxation and greater elimination of promoting factors or crystals, so in fact there is still a lack of evidence proving the clinical benefit of this agent. ²^6–28 Along with water intake, Excessive sodium consumption was also one of the items most cited by most participants as a risk factor for stone precipitation, both in the present and in the study by Marsh et al., 2019. High sodium consumption contributes to hypercalciuria, a since these elements share the same transport mechanisms along the proximal tubule.²⁹ It is important to note that the increase in fluid consumption and the reduction in sodium consumption are also widespread guidelines for general health maintenance, so we cannot rule out the possibility that the highest percentage of correct answers in these items presents a relationship of confusion regarding general aspects of health, to the detriment of specific guidelines for renal lithiasis. This argument is supported by the fact that most individuals (83.4%) also indicated,

Although the majority of lithiasis patients (61.5%) did not know the type of stone they had, among those who did, calcium oxalate stone was the most reported by the participants. In fact, studies show that this is the most prevalent type of calculus. ⁹ With regard to nutritional management, as it is a specific term, lithiasis patients were the ones who most reported having heard about oxalate, however, when faced with the food list, the identification of oxalate sources was similar among the patients. groups. This data differs from what was expected and is worrying, given the high occurrence of oxalate-based stones. In the study by Marsh et al. (2019), individuals with a history of calcium oxalate-based stones knew to indicate the source foods (almonds, spinach, beetroot and rhubarb) more than non-lithiasic individuals. In addition to reducing oxalate intake, it is also important that patients with renal lithiasis, especially oxalate-based, maintain adequate calcium intake. In this context, a very small percentage of individuals, with or without lithiasis, do not understand that milk chocolate would be more suitable than dark chocolate for individuals with oxalate-based lithiasis. Mendonça et al. (2003) observed a 20% increase in oxaluria in lithiasics who consumed dark chocolate and 9% in those who consumed milk chocolate, probably due to the chelating power of calcium on oxalate. ³⁰ do not understand that milk chocolate would be more suitable than dark chocolate for individuals with oxalate-based stones. Mendonça et al. (2003) observed a 20% increase in oxaluria in lithiasics who consumed dark chocolate and 9% in those who consumed milk chocolate, probably due to the chelating power of calcium on oxalate. 30 do not understand that milk chocolate would be more suitable than dark chocolate for individuals with oxalate-based stones. Mendonça et al. (2003) observed a 20% increase in oxaluria in lithiasics who consumed dark chocolate and 9% in those who consumed milk chocolate, probably due to the chelating power of calcium on oxalate. ³⁰

Calcium plays a chelating power on oxalate in the intestine, forming an insoluble complex that is eliminated in the feces. Although most stones are based on calcium, consumption of this mineral towards adequate intake (1000 to 1200mg/day) has been associated with a lower incidence of kidney stones. On the other hand, low dietary calcium intake can result in a negative calcium balance and bone loss, which can also induce hypercalciuria.¹⁰ Despite a small frequency of individuals believing that the low consumption of calcium and a factor promoting kidney stones, most of these individuals were lithiasic. The myth that lithiasis patients need to restrict calcium is still widely publicized in non-technical/scientific circles. In a study that investigated information not obtained by nutritionists, it was found that the most erroneously remembered recommendation was related to the restriction of calcium consumption.³⁰ In an era where reliable information is in abundance, dietary guidelines must be specific/individualized and focused on the priority of the patient. patient to improve the implementation of the diet and, consequently, the prevention of the formation of new kidney stones. ²³

Another concern about information about nutrition and oxalate stone formation is the indiscriminate use of vitamin C supplements.According to the Federal Pharmacy Council of Brazil, compared to the months of January and March 2019, in 2020 there was an increase of almost 180%. This behavior was observed due to the coronavirus disease 2019 (COVID-19) pandemic. Most individuals who use these supplements believe that their consumption in high doses is safe and beneficial.³¹ It is known that high doses of vitamin C should be avoided, since this vitamin can be metabolized to oxalate, being associated with an increased risk of kidney stone formation.33Thus, in renal lithiasis, it is recommended that the supply of vitamin C comes from natural sources.^10,17

Hypocitraturia is one of the most common urinary metabolic disorders among patients with renal lithiasis and the use of citrus fruits shows the benefit of increasing citraturia. ³⁴ About 50% of participants, surprisingly with no significant differences between groups, reported having heard of citrate. The frequency of identification of food sources such as oranges and lemons was low, close to 35%. However, melon, a non-citrus fruit with a high citrate content, was cited by only 3.5%. ³⁴ Although it may mean a low level of knowledge about citrate sources, this result is justified by the difficulty, in clinical practice, in identifying citrate sources, since this data is not available in food composition tables. Other non-citrus fruits like coconut water, were also evaluated to reverse hypocitraturia.36 Given the above, encouraging the regular consumption of fruits in general can favor the treatment of hypocitraturia and the prevention of recurrence of kidney stones due to other factors such as increased potassium intake and alkaline load. On the other hand, protein sources are recognized for their acidogenic potential and, when associated with a low consumption of vegetables, it reduces urinary pH, which can increase the risk of precipitation of some types of kidney stones. In the present study, half of the participants, with no differences between groups, recognized high protein consumption as a promoting factor for stone formation. A similar proportion, however, more frequent among non-lithiasic,

The main limitation of the present study is the use of a non-validated questionnaire for data collection. It is noteworthy that, to our knowledge, there is no standardized and validated questionnaire to assess individuals' knowledge about diet and kidney stones. The questionnaire used was formulated based on the researchers' experience on the subject and includes the main nutritional guidelines reported in the scientific literature. On the other hand, this is the first study carried out in Brazil that assesses knowledge, comparing it between individuals affected or not by the disease.

In conclusion, the present study shows that there are gaps in knowledge about nutritional guidelines in patients with renal lithiasis, which is even more worrying due to the few differences when compared to non-lithiasis patients. Despite the high recurrence rate, many patients did not receive specialized and individualized nutritional guidance. This data reflects the reality of the treatment of renal lithiasis in the country and reinforces the importance of the nutritionist in the prevention and treatment of renal lithiasis.

Competitive Interests:

Not applicable.

Authors' Contributions:

The authors made the following contributions: CIR collected the data, performed the statistical analysis, interpreted the data, wrote and revised the manuscript. RTB conceived the idea, collected the data, performed the statistical analysis, interpreted the data, wrote and revised the manuscript. ANM conceived the idea, collected the data, performed the statistical analysis, interpreted the data and wrote the manuscript. All authors read and approved the final manuscript.

Financing:

Not applicable.

Availability of data and Materials:

Pubmed, Scielo, Google Scholar, Medline.

The following were used: internet access, prints and stationery itens such as sheets sulfites and oens, totaling R$200,00. This Project is funded own, therefore the costs are the responsability of the researchers.

Romero V, Akpinar H, Assimos DG. Kidney stones: a global picture of prevalence, incidence, and associated risk factors. Rev Urol. 2010; 12:86-96.
Petroianu A, Neto JEO. Epidemiological data on renal lithiasis at a referral hospital in Belo Horizonte, Minas Gerais. Medicine, Ribeirão Preto, 2001; 34:85-88.
Korkes F, Silva JL, Heilberg IP. Cost of hospital treatment of urinary lithiasis for the Brazilian Unified Health System. Einstein. 2011;9(4):518-22.
Worcester EM, Coe FL. Calcium Kidney Stones. Clinical Practice. N Engl J Med., 2010; 63:954-63.
Sakhaee K, Maalouf NM, Sinnott B. Clinical: review. Kidney stones 2012: pathogeny, diagnosis, and management. J Clin Endocrinol Metab. 2012; 97:1847-1860.
Shang W, Li L, Ren Y, et al. History of kidney stones and risk of chronic kidney disease: a meta-analysis. PeerJ. 2017; 5:e2907.
Rendina D, De Filippo G, D'Elia L, Strazzullo P. Metabolic syndrome and nephrolithiasis: a systematic review and meta-analysis of the scientific evidence.J Nephrol. 2014; 27(4):371-6.
Sakhaee K. Nephrolithiasis as a systemic disorder. Curr Opin Nephrol Hypertens. 2008; 17:304-9.
Worcester EM, Coe FL. Clinical practice. Calcium kidney stones. N Engl J Med. 2010; 363:954-963.
Baxmann AC, Carvalho M, Heilberge IP. Nutrition in Renal Lithiasis. In: Riela MC, Martins C. Nutrition and the kidney. 2nd edition. Rio de Janeiro: Guanabara Koogan; 2013. 291-295.
Santos FM, Peres, AK, Mandotti MR, Peres LAB. Metabolic investigation in patients with nephrolithiasis. Einstein (Sao Paulo). 2017; 15(4):452-456.
Taylor EN, Stampfer MJ, Curhan GC. Dietary factors and the risk of incident kidney stones in men: new insights after 14 years of follow-up. J Am Soc Nephrol. 2004; 15:3225-32.
Massey LK, Whiting SJ. Dietary salt, urinary calcium, and kidney stone risk. Nutri Rev. 1995; 53:131-9.
Heilberg IP, Schor N. Renal Stone Disease: Causes, Evaluation and Medical Treatment. Arq Bras Endocrinol Metab. 2006; 50(4): 823-831.
Ferraro PM, Taylor EN, Gambaro G, Curhan GC. Dietary and Lifestyle Risk Factors Associated with Incident Kidney Stones in Men and Women. J Urol. 2017; 198(4): 858–863.
Turney BW, Appleby PN, Reynard JM, Noble JG, Key TJ, Allen NE. Diet and risk of kidney stones in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC).Eur J Epidemiol. 2014;29:363–9.
Meschi T, Maggiore U, Fiaccadori E, Schianchi T, Bosi S, Adorni G, et al. The effect of fruits and vegetables on urinary stone risk factors. Kidney Int. 2004; 66:2402-10.
Ahmed MH, Ahmed HT, Khalil AA. Renal stone disease and obesity: what is important for urologists and nephrologists? RenFail. 2012; 34:1348–54.
Ando R, Suzuki S, Nagaya T, et al. Impact of insulin resistance, insulin and adiponectin on kidney stones in the Japanese population. Int J Urol. 2011;18:131–8.; 9.
Cheungpasitporn W, Thongprayoon C, O'Corragain OA, et al. The risk of kidney cancer in patients with kidney stones: a systematic review and meta-analysis. QJM 2015; 108:205–12.
Hess B. Acid–base metabolism: implications for kidney stone formation. Urol Res. 2006; 34:134–138.
Romero V, Akpinar H. and Assimos, DG (2010) Kidney Stones: A Global Picture of Prevalence, Incidence, and Associated Risk Factors Kidney Stones: A Global Perspective. Reviews in Urology, 12, e86-e96.
Penniston K, Nakada SY. Expectations of treatment and health-related quality of life in care educators. Current Opinion in Urology: 2016 - Volume 26 - Edition 1 - p 50-55
Cupisti A, Meola M, D'Alessandro C, Bernabini G, Pasquali E, Carpi A, et al. Insulin resistance and low urinary citrate excretion in calcium stone formers. Biomed Pharmacother. 2007 Jan; 61(1):86-90.
Marsh et al.,Effect of dietary treatment and fluidintake on the prevention of recurrent calcium stones and changes in urine composition: ameta-analysis and systematic review. 2021 Apr; 16 (4) 2021.Public Library of Science (PLoS).
Barros ME, Lima R, Mercuri LP, Matos JR, Schor N, Boim MA. Effect of extract of Phyllanthus niruri on Crystal deposition in experimental urolithiasis. Urol Res 2006; 34:351-357.
Nishiura JL, Campos AH, Boim MA Heilberg IP, Schor N. Phyllanthus niruri normalizes elevated urinary calcium levels in calcium stone forming (CSF) patients. Urol Res 2004; 32: 363-366.
Micali S, Sighinolfi MC, Celia A, De Stefani S, Grande M, Cicero AF, Bianchi G. Can Phyllanthus niruri affect the efficacy of extracorporeal shock wave lithotripsy for renal stones? A randomized, prospective, long-term study. J Urol. 2006 Sep;176(3):1020-2.
Aguiar M, Bernardo E. D, de S Costa F N. High sodium intake: impact on the health of the adult Brazilian population. Research, Society and Development. 10(14) e440101422132, 2021.
Lopes VM, Souza BDR, Souza VM, Benevides JM. Antinutritional factors in foods: Review. Food and Nutrition Security, Campinas 18(2): 67-79. 2011.
Santos, JT, Krutzmann, MW, Bierhals, CC, & Feksa, LR (2019). THE EFFECTS OF VITAMIN C SUPPLEMENTATION. Knowledge Online Magazine, 1, 139–163.
Vieira DR, Freitas RF, France SD. PREVENTION OF URINARY LITHIASIS BY POTASSIUM AND MAGNESIUM CITRATES REPLACEMENT THERAPY: case report. Magazine of the Vale do Rio Verde University, Três Corações, Jul. 2017.15(1), p. 49-53.
Baia Lda C, Baxmann AC, Moreira SR, Holmes RP, Heilberg IP. Noncitrus alkaline fruit: a dietary alternative for the treatment of hypocitraturic stone formers. J Endourol. 2012 Sep;26(9):1221-6. doi: 10.1089/end.2012.0092. Epub 2012 Jun 4.
Patel RM, Jiang P, Asplin J, Granja I, Capretz T, Osann K, Okhunov Z, Landman J, Clayman RV. Coconut Water: An Unexpected Source of Urinary Citrate. Biomed Res Int. 2018 Nov 1; 2018:3061742.

Tabela 1 – Dados sociodemográficos e de saúde de indivíduos litiásicos e não litiásicos, 2020.

Dados sociodemográficos	Total	Litiásicos	Não litiásicos	P
Idade, anos	34,5 (28-75,41)	35 (29,5–40,5)	33 (26,5–41,5)	0,169
Sexo feminino - n (%)	216 (76,3)	141 (81)	75 (68,8)	0,019
Ensino superior completo - n (%)	77 (27,2)	44 (25,3)	33 (30,3)	0,000
Casados/União estável - n (%)	138 (48,8)	95 (54,6)	43 (39,4)	0,072
Brancos - n (%)	181 (64)	116 (66,7)	65 (59,6)	0,062
Residem no estado de SP - n (%)	185 (65,4)	92 (52,9)	93 (85,3)	0,000
Dados de saúde
IMC, kg/m²	26,7 (23,4-30,5)	27,5 (23,9–31,3)	25,6 (23,1– 29,0)	0,001
Pré diabetes / Diabetes - n (%)	21 (7,4)	13 (7,5)	8 (7,3)	0,967
Hipertensão arterial - n (%)	43 (15,2)	33 (19)	10 (9,2)	0,026
Hiperuricemia/Gota - n (%)	16 (5,7)	16 (9,2)	0 (0)	0,003
Dislipidemia - n (%)	41 (14,5)	27 (15,5)	14 (12,8)	0,534

IMC – ÍNDICE DE MASSA CORPORAL

Tabela 2 - Comparação do conhecimento sobre a influência da alimentação na nefrolitíase entre indivíduos litiásicos e não litiásicos, 2020.

Pergunta	Total	Litiásicos	Não litiásicos	P
A alimentação influencia na formação de cálculos renais	243 (85,9)	141 (81)	102 (93,6)	0,003
Aumentar a ingestão de líquidos pode diminuir a formação de cálculos renais	257 (90,8)	153 (87,9)	104 (95,4)	0,034
Não há efeito cientificamente comprovado do chá de quebra pedras	97 (34,3)	63 (36,2)	34 (31,2)	0,388
O consumo elevado de proteína pode aumentar a formação de cálculos renais	148 (52,3)	98 (56,3)	50 (45,9)	0,087
O baixo consumo de cálcio pode aumentar a formação de cálculos renais	79 (27,9)	52 (29,9)	27 (24,8)	0,018
O consumo elevado de sódio pode aumentar a formação de cálculos renais	219 (77,4)	140 (80,5)	79 (72,5)	0,119
O consumo elevado de óleos e gorduras não tem efeito direto sobre a formação de cálculos renais	47 (16,6)	27 (15,15)	20 (18,3)	0,534
O uso regular de suplementos de vitamina C pode aumentar a formação de cálculos renais	82 (29)	55 (31,6)	27 (24,8)	0,218
O consumo de caroços de frutas e verduras não tem efeito sobre a formação de cálculos renais	84 (29,7)	48 (27,6)	36 (33)	0,330
O consumo regular de frutas, verduras e legumes pode diminuir a formação de cálculos renais	149 (52,7)	83 (47,7)	66 (60,6)	0,035
Ouviram falar de oxalato?	155 (54,8)	114 (65,5)	41 (37,6)	0,000
São fontes importantes de oxalato Espinafre Amêndoas Leite Cacau e derivados Chuchu Não sabem	81 (28,6) 33 (11,7) 257 (90,8) 89 (31,4) 280 (98,9%) 115 (40,6)	54 (31,0) 23 (13,2) 154 (88,5) 60 (34,5) 172 (98,9) 93 (53,4%)	27 (24,8) 10 (9,2) 103 (94,5) 29 (26,6) 34 (31,2) 75 (68,8%)	0,257 0,302 0,090 0,165 0,853 0,010
Chocolate ao leite é o mais indicado para pessoas com cálculos à base de oxalato	25 (8,8)	10 (5,7)	15 (13,8)	0,021

Tabela 2 - Comparação do conhecimento sobre a influência da alimentação na nefrolitíase entre indivíduos litiásicos e não litiásicos, 2020 (continuação).

Ouviram falar de citrato?

147 (51,9)

95 (54,6)

52 (47,7)

0,259

São fontes importantes de citrato

Limão

Laranja

Abacaxi

Melão

Uva

Não sei

104 (36,7)

101 (35,7)

84 (29,7)

10 (3,5)

16 (5,7)

113 (39,9)

69 (39,7)

66 (37,9)

56 (32,2)

8 (4,6)

6 (3,4)

76 (43,7)

35 (32,1)

28 (25,7)

2 (1,8)

10 (9,2)

37 (33,9)

0,201

0,321

0,245

0,326

0,042

0,104

Os números apresentados referem-se ao n (%) de respostas afirmativas para o item em questão.

No competing interests reported.

Knowledge of the population on the influence of diet on renal lithiasis

Status:

Version 1

Abstract

Introduction

Methodology

Statistical analysis

Results

Discussion

Declarations

References

Tables

Additional Declarations

Status:

Version 1