The role of education in the association between self-rated health and levels of C-reactive protein: a cross-sectional study in rural areas of China

Abstract

ObjectivesThis study aims to examine the association between self-rated health (SRH) and levels of C-reactive protein (CRP) among adults aged 45 to 101 years old in rural areas of China, and to explore the role of education in the association.DesignCross-sectional study.SettingThe study population was derived from two databases in China: Nanping project (NP) and the China Health and Retirement Longitudinal Study (CHARLS).ParticipantsThere were 646 participants from a rural area of Nanping (NP) and 8555 rural participants from a national representative sample of China (CHARLS).MethodsCRP was measured using a high sensitivity sandwich enzyme immunoassay in the NP and immunoturbidimetric assay in the CHARLS. SRH was assessed by SRH questionnaires and categorised into good and poor. Education was measured by the maximum years of schooling and dichotomised into illiterate and literate. Multivariate linear regression models were used to study the associations.ResultsCompared to people with good SRH, those with poor SRH had higher levels of CRP in NP (β=0.16, 95% CI −0.02 to 0.34) and in CHARLS (β=0.07, 95% CI 0.02 to 0.11) after adjusting for potential confounders. Similar findings were observed in the pooled population (β=0.08, 95% CI 0.03 to 0.12), especially in men (β=0.13, 95% CI 0.06 to 0.20) and in literate people (β=0.12, 95% CI 0.06 to 0.18).ConclusionPoor SRH may be a predicator of elevated levels of CRP among middle-aged and older people in rural areas, especially in men and literate people.

Self-rated health, socioeconomic status and all-cause mortality in Chinese middle-aged and elderly adults

“…Specifically, the gene scores for several diseases which increase the new-onset risk of death (e.g., ischemic heart disease, macrovascular stroke and type 2 diabetes) were also associated with SRH 38 . Thirdly, worse SRH, as a sensitive indicator of health, could synthetically reflect their poor physical status and social support, which may limit the contact with health services and induce mental stress 39 . Stress is known to be associated with low-grade chronic inflammation and elevated level of pro-inflammatory cytokines 40 .…”

Sex differences in the association between self-rated health and high-sensitivity C-reactive protein levels in Koreans: a cross-sectional study using data from the Korea National Health and Nutrition Examination Survey

“…Shanahan et al [8] suggested that an elevated hs-CRP level is associated with poor SRH. Conversely, other studies have suggested that poor SRH is associated with elevated hs-CRP levels [10]. Moreover, other studies have reported an association between albumin levels, hemoglobin levels, white blood cell counts, and HDL-cholesterol levels [11].…”