[Serum total cholesterol levels and eligibility for long-term care insurance: a prospective cohort study of the Tsurugaya project].

The purpose of this study was to examine the relationship between serum total cholesterol levels and certification eligibility for long-term care insurance in elderly Japanese individuals. The Tsurugaya Project was a comprehensive geriatric assessment conducted for community-dwelling elderly individuals aged ≥70 years in the Tsurugaya area, Sendai, Japan. Of the 2,925 inhabitants, 958 subjects participated in the Tsurugaya Project. For this analysis, we used 827 subjects who gave informed consent and were not qualified for long-term care insurance at the time of the baseline survey. Subjects were followed up for 6 years. We classified the subjects into 4 quintiles and used the fourth quintile (212-230 mg/dL) as a reference for statistical analysis. We used Cox proportional hazards model to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of certification eligibility for long-term care insurance according to total cholesterol levels in serum. During 6 years of follow-up, a total of 214 subjects were qualified for long-term care insurance certification. The lowest serum total cholesterol level (<177 mg/dL) was significantly associated with increased eligibility for long-term care insurance certification. Compared with the fourth quintile, multivariate HRs (95%CIs) of long-term care insurance certification were 1.91 (1.23-2.98), 1.36 (0.85-2.18), 0.99 (0.62-1.56), 1.38 (0.88-2.17), for <177 mg/dL, 177-194 mg/dL, 195-211 mg/dL, and ≤231 mg/dL, respectively. Moreover, the association was statistically significant even after excluding subjects with a history of liver disease or cancer, an abnormality in the liver function test, or high levels of high-sensitivity C-reactive protein. Low serum total cholesterol levels were significantly associated with increased eligibility for long-term care insurance certification even after adjusting for a variety of confounding factors.