The inverse association between age and cholesterol level among older patients: the role of poor health status.

BACKGROUND

The total cholesterol concentration decreases with age in older people. The reasons for this phenomenon are controversial. This study investigated the hypothesis that poor health status is a determinant of the inverse association between age and cholesterol in older persons.

METHODS

Cross-sectional study of 2,486 (53% women) older medical patients (> or =65 years) admitted at 35 centers of the Gruppo Italiano di Farmacovigilanza nell'Anziano (GIFA) study in Italy. Total cholesterol was measured on the first day after admission to the hospital. Disease burden and comorbidity were assessed by the Charlson index; low serum albumin and iron were considered markers of frailty and poor health.

RESULTS

In men there was a significant, inverse age-cholesterol relationship (-0.97 mg/dl per year, p<0.001). In women the association was nonlinear and cholesterol significantly decreased after the age of 75 (-0.95 mg/dl per year, p<0.005). In multiple linear regression analysis, indicators of poor health accounted for almost two thirds of the crude effect of age on the cholesterol level in both men and women (adjusted coefficients for age were: for men, -0.38 mg/dl per year, p = 0.044; for women after the age of 75, -0.37 mg/dl per year, p = 0.205). The unadjusted probability of having low cholesterol significantly increased with age among men (p for trend <0.005). In multiple logistic regression, indicators of poor health were strongly associated with low cholesterol in both men and women. After adjusting for indicators of poor health, the association between age and low cholesterol in men was no longer present.

CONCLUSION

These findings suggest that the age-dependent reduction of cholesterol often observed in clinical and epidemiologic studies is substantially explained by the effect of poor health status. Low cholesterol in older persons may be a marker of poor health.