This is a nationwide population-based report on the awareness, treatment, control and relevant determinants of dyslipidemia among middle and older aged Chinese adults. Main findings include: Sixty-four percent of subjects with dyslipidemia were aware of their condition, of whom 18.9% received pharmacological treatment, and of whom 7.3% had controlled lipids. Treatment and control proportions in both residences were higher in women than men. The following determinants showed higher likelihood for awareness: women, urban residence, junior or middle school, health insurance, family history of dyslipidemia, history of stroke, central obesity and history of CHD. Women, health insurance, history of CHD, current drinking and personal history of stroke showed positive association with treatment. Dyslipidemia control saw significant relationships with age groups, women, urban residence, northern zone, health insurance, stroke belt, overweight, and general obesity.
If our results are juxtaposed with the ‘rule of halves’ framework, 10 obviously, the proportion of treatment (18.9%) and control (7.3%) observed is well below the 50% benchmark. Although, our result suggests that awareness has improved, more actions are needed to scale-up and improve treatment of lipid disorders in China. The present results on awareness, treatment and control were higher compared with previous studies in China9,22 Further, we recorded higher awareness and treatment, but lower control values for dyslipidemia compared with other studies. 7,8 The low level of control observed in the current study could partly be explained by the low treatment value observed despite evidences available on the therapeutic use of statins,22,23 or due to poor adherence to medications.24 The low level of control seen may also reveal some level of ineffectiveness in the current treatment approaches. Therefore, strategies to improve patient’s adherence to medication regimens, the increased use of treatment protocols that ensure adequate treatment and access to more affordable medications should be targeted. Notably, drugs therapy alone does not control dyslipidemia completely. Measures such as lifestyle modifications and good nutrition are effective in controlling high blood lipids. 25–27 There is also the need to place more emphasis on prevention. Efforts are needed to scale-up both targeted and opportunistic screening programs, health promotions, and provision of more effective cholesterol-modifying medications for use. Early identification of populations who are not only at risk, but who could benefit most from preventive measures is crucial. Hence, the use of both pharmacological and non- pharmacological approaches are preferred for effective dyslipidemia management. The low treatment and control identified present a great opportunity for China to improve its dyslipidemia management strategy.
In the present study, subjects aged 40–49 years had higher odds for dyslipidemia control than older participants. This results was in accord to data from a Korean study where younger adults were more likely to have controlled LDL-C than the elderly.28 However, many reverse results have been reported between older ages and dyslipidemia control. 7,22,29 Again, differing from our findings, a positive association between aging and the control of chronic diseases such as hypertension has been reported. 30 Our results may support the finding that dyslipidemias such as raised TC control rates may differ depending on the participants and country, and rates may range from 18–100%.31
Consistent with prior reports, 22,29 we showed that women were more likely than men to have dyslipidemia awareness, treatment and control. Similarly, two studies on the management of raised LDL-C indicated that women recorded higher likelihood of awareness, treatment and control. 6,32 Behavioral differences between the sexes could partly explain this results, as women are reported to seek healthcare services more often than men. 6 An earlier study 18 reported no relationship between dyslipidemia treatment and place of residence, but our study demonstrated positive association between dyslipidemia awareness or treatment with urban residence. Similarly, studies in Malaysia and Thailand, 33,34 showed high awareness and treatment levels between raised LDL-C and urban centers. Further, findings from studies in low and middle-income countries have reported lower values of dyslipidemia awareness and treatment in rural settings. 19,35 The high awareness and treatment levels found in urban areas may be attributed to wealthier and better educated populations usually found in cities. 36 Again, it may buttress the evidence of difficult access to health care common in rural areas. 11 Hence, health promotion programs should target areas such as rural settings with limited healthcare resources. The lower level of control seen among urban populations merits some explanation, albeit difficult, as poor adherence to treatment regimens may play a role. Junior/middle school education level was independently related to dyslipidemia awareness, but not treatment and control. This result contradicts previous reports.7,18 The mechanisms underlying the link between length of education and awareness of dyslipidemia is not clear. Nevertheless, a previous report suggested that education is the finest socioeconomic status index and can predict CVD’s awareness.37 Future studies are warranted to examine this results.
Health insurance coverage was associated with dyslipidemia awareness and treatment, but not control. In line with our finding, a US study found respondents without health insurance with lower levels of awareness and treatment for elevated LDL-C. 38 Insured individuals were more likely to receive treatment in another study. 38 Once dyslipidemia is seen, effective management follows, and health insurance fundamentally addresses socioeconomic barriers to effective healthcare.38 The negative relationship that existed between having health insurance and dyslipidemia control in the current study was inconsistent with earlier reports,6,38,39 since health insurance is related to improved CV risk factor control and outcomes.39
Residing in a high compared with low-income region was associated with less dyslipidemia awareness, but high treatment level. This may suggest that high-income region is an independent driver for treatment. High- income communities have been reported to demonstrate high association with treatment of chronic conditions.40 It may be that, the availability or easier access to health facilities in high-income regions facilitates the usage of health services.
From this study, staying in northern China was an independent determinant for dyslipidemia control. A study determined that stroke prevalence was significantly higher in the northern parts of China,41 and living in the north was associated with high dyslipidemia prevalence.8,42 We speculate that, the high prevalence of stroke and dyslipidemia found in the north could positively affect inhabitants’ behaviors towards treatment and yield favorable results. We showed that lower likelihoods of dyslipidemia awareness, treatment, and control were related to living in the stroke belt region of China. This results was dissimilar to that of the REGARDS study 43 where lower control rate was found outside the stroke belt region. This finding may indicate that effective and efficient management of lipid disorders may not be related to the stroke belt zone. Studies are required to further investigate why awareness and treatment of dyslipidemia were less likely in the stroke belt zone. We observed a negative association between dyslipidemia awareness and obesity. This was consistent with an earlier study.44 Speculatively, the low awareness level seen could be due to the natural history of the disease, or one’s poor attitude towards healthcare. Overweight and general obesity were significant negative predictor for dyslipidemia control, these were similar to earlier researches.7,18 An explanation could be that dyslipidemia control is difficult in individuals with more than normal body weight. Central obesity was a significant positive predictor of dyslipidemia awareness. This finding might reflect efforts instituted by healthcare systems to improve screening for blood lipid disorders among high-risk individuals.45
Subjects with a personal history of CHD or stroke were more likely to know or receive treatment for dyslipidemia. Similarly, a previous study observed that personal history of ASCVDs were associated with higher use of statins.46 In addition, other reports [35–37] had observed that people who experienced cardiovascular events often become more focused on their health, especially on CVD risk factors such as dyslipidemia. Therefore, these individuals are more likely to comply with lipid-modifying medications and/ or lifestyle interventions.
Patients with family history of dyslipidemia in their immediate family had the strongest independent association of awareness in this study. This is in line with the result of He et al. where persons with a family history of dyslipidemia had higher likelihood of awareness.7 It has also been found that the chances of diagnosis and treatment of dyslipidemia is generally higher in high-risk individuals including those with CVDs. Predictably, family members would be more mindfulness and watchfulness of dyslipidemia and doctors would pay more attention to these patients.7
Subjects with diabetes were less likely to get treatment for dyslipidemia. A reverse results was seen by Li et al. 41 where dyslipidemia treatment among persons with diabetes was up to about 55.9%. We speculate that there persons did not receive adequate treatment due to wrong attitude towards the disease or poor adherence to treatment.47,48. The low likelihood of treatment could also be as a result poor knowledge about diabetic dyslipidemia among patients. Therefore, it is imperative for health workers to intensity health education and pay more attention to detect lipid disorders in suspected co-morbid patients. This study found that current drinking was associated with dyslipidemia treatment. This was dissimilar to findings in the Jilin province of China, 7 where current drinking was associated with low level of treatment. We speculate that these individuals were already in the health service system, so they were more likely to be treated with medication.