The results of the present study suggest that several variables including caste system, education, occupation, tobacco, alcohol, physical activity, blood pressure, and other ailments may impact the risk of CKDu in the Uddanam region.
In our study, the caste system is significantly associated with the risk of CKDu, and the castes that were in the bottom of the hierarchical pyramid of the caste system were more prone for CKDu. This finding is in accordance with the results of other related studies, lower caste groups such as scheduled caste and scheduled tribes have poor health behaviors [22], lower life expectancies [23],[24], and a higher frequency of abnormal kidney function [25]. We also observed that castes in the Uddanam region that are at the bottom of the hierarchical pyramid of the caste structure are not consume a proper nutritious diet and not following healthy habits not because of anything else but they are basically poor and it is poverty per se rather than anything else that is predisposes these castes to CKDu.
In the current study, education was significantly associated with the risk of CKDu. This finding is in accordance with the results of other studies. They suggested that education is one of the social determinants that reflect the health of the population [26], and different levels of education may affect the health of individuals differently [27], [28]. One-third of the people in this Uddanam region were illiterate, so no or less education is a very important indicating risk factor for CKDu.
The other variable that was associated with the risk of CKDu was occupation. This finding is in accordance with the results of other studies. They suggested that those involved in manual or agricultural work [29] and unskilled workers [30] were at risk of developing CKD. In this Uddanam region the farmers, and daily wage laborers involved in the culturing of paddies and cashews were more prone to developing CKDu. Therefore physically hard work involving occupation is another risk factor for CKDu.
One of the variables physical activity was negatively associated with the risk of CKDu. This finding is in accordance with the results of several other studies. They suggested that physical activity may protect against kidney disease [31], a higher exercise score was significantly associated with a lower prevalence of in proteinuria both men and women [32], and increased physical activity might have a survival benefit in the CKD population [33]. In this Uddanam region, greater percentages were involved in physical activities, so it is protective against CKDu.
After controlling for the other variables the tobacco was involved very low leveled risk of CKDu. This finding is in accordance with the results of other studies. They suggested that people who had a habit of smoking had an increased risk of developing CKD [34], [35]. In this Uddanam region, nearly half of the people had the habit of smoking or chewing tobacco, so tobacco was one of the risk factors for CKDu.
The present study also showed that alcohol was associated with the risk of CKDu at a very low level. This finding is in accordance with the results of other studies. They suggested that people who consume locally made alcohol [25] and who have a habit of drinking alcohol had an increased risk for developing CKDu [35], [27]. In this Uddanam region fewer individuals had habit of drinking alcohol and we did not observe any locally made alcohol and observed that more male persons had a habit of drinking palm tree derived mild alcoholic drinks.
Another important result of the current study is the association between hypertension and the risk of CKDu. Our result is consistent with the results of several other studies. They suggested that people who had blood pressure above normal levels [13], [36]and who had history of hypertension [27], [28], [37] had an increased risk for developing CKD. In this Uddanam region, nearly half of the persons had hypertensive conditions, so hypertension is an important cause and may accelerate the progression of the CKD to ESRD (end stage renal disease).
In our study, the variable any other ailment associated with CKD had a significant association with the risk of CKDu. In this Uddanam region, gastric abnormalities, eye abnormalities and thyroid and asthma are the main ailments observed in CKDu patients. This finding is in accordance with the results of several other studies. They suggested that upper gastric abnormalities common among kidney patients [38], retinopathy and its features can affect the level of kidney function [39], and ocular manifestations develop in CKD patients [40] and hypothyroidism is a risk factor for CKD and its progression[41].Patients with asthma are at risk of developing CKD [42].In this Uddanam region, fewer of patients had other ailments along with CKD.
The water intake between the two groups (case and control) was significant differenent. The negative mean difference suggests that the first group (case = 9.56) tends to have lower average water intake compared to the second group (control = 10.81). This result is in accordance with other studies, Lower total water intake was associated with chronic kidney disease[43] and increased water intake may benefit kidney function [44].A significant difference was observed in the costs of transport to the hospital, diagnosis, and medicine between cases and controls, and based on the present analysis, the increase in severity of the disease, the spending cost of medical expenses also increased, stage − 4 and stage − 5 CKDu patients spent more money to treat disease than stage − 3 and stage 1 and 2 CKDu patients compared to controls with and without any other ailments and acute or chronic diseases. These finding is also in accordance with the results of several other studies. They suggested that the financial impact of CKD is large, with particularly high costs relating to RRT (renal replacement therapy) and cardiovascular complications [45] and the societal direct and indirect costs of CKD and end-stage renal disease are substantial and increase throughout disease progression [46]. In the Uddanam region, patients’ average spending cost per month on medicines in both mandals is nearly Rs. 3000. Thus patients have a greater burden on the purchase of medicines.
Strengths and limitations of our study
The following aspects are considered the strengths of our study. The sample size was fairly large and samples were taken from two different but adjoining mandals. Interviewing the patients and controls by directly approaching them or through local medical personnel. Confirmation of the CKDu condition was performed by government Medical officials. Limitations of the study are as follows 1.We considered the serum creatinine level as primary proof for confirming the CKDu condition 2. GFR and remaining biochemical parameters are neglected because they were already on medication and registered as CKDu patients in PHC medical records. We failed to obtain a history of antibiotics and the use of other pain killers.