Cholesterol and all-cause mortality in Honolulu

Effect of cholesterol on mortality and quality of life up to a 46-year follow-up

The effect of cholesterol level on the health of older people is a matter of debate, probably because of the bidirectional association. We investigated this paradox in a long-term study. The baseline assessments of the Helsinki Businessmen Study (a cohort of mainly business executives, born 1919 to 1934) included the total cholesterol value and other cardiovascular risk factors from 1964 to 1973. These men were followed up for ≤46 years (through January 2010). During the follow-up period, the cholesterol value was assessed by self-report in 2000 (n = 1,292). Mortality was ascertained from the national registers, symptoms, and health-related quality of life with RAND-36 from questionnaires in 2000. A total of 3,277 healthy men without chronic diseases at baseline were included in the analyses. The median total cholesterol concentration at baseline was 6.5 mmol/L (251 mg/dl) (interquartile range 5.8 to 7.3 mmol/L, 224 to 282 mg/dl) and, in 2000, was 5.2 mmol/L (201 mg/dl) (interquartile range 4.6 to 5.9 mmol/L, 178 to 228 mg/dl). During the follow-up period, 1,773 men (54%) died. A strong and graded relation was found between the cholesterol level and total mortality, with the men with a cholesterol level ≤4 mmol/L (154 mg/dl) having the lowest mortality. In all, the men with the lowest cholesterol gained the most life years. However, no association was found with the cholesterol level in 2000 (when 16% were using statins) and subsequent mortality. The lowest (≤4 mmol/L) cholesterol value in midlife also predicted a higher score in the physical functioning scale of RAND-36 in old age. In conclusion, a low total cholesterol value in midlife predicts both better survival and better physical functioning in old age.

Low cholesterol, mortality, and quality of life in old age during a 39-year follow-up

OBJECTIVES

We assessed the impact of serum cholesterol level in early midlife on total mortality during up to 39 years of follow-up and on the quality of life (QoL) in old age.

BACKGROUND

Total effects of low serum cholesterol on health have been in dispute, especially in elderly persons, and there are few data on the long-term effects of low cholesterol on QoL.

METHODS

The cohort consisted of 3,277 healthy businessmen age 30 to 45 years at baseline (1960s). In addition to baseline, serum cholesterol values were available for part of the cohort in 1974, 1986, and 2000. The QoL was assessed in 80.9% of survivors (n = 1,820, mean age 73 years) with a RAND-36 (SF-36) QoL questionnaire in 2000. Mortality up to 2002 (n = 1,173) was retrieved from national registers.

RESULTS

Cholesterol was clearly reduced in survivors during follow-up, except in the lowest baseline serum cholesterol group. Baseline cholesterol predicted 39-year total mortality in a graded manner (p < 0.0001), and a value < or =5.0 mmol/l was associated with a 25% reduction in total mortality. In old age, the physical component summary score of RAND-36 was significantly (p = 0.02) higher (better) in the lowest baseline cholesterol group; no difference was found in the mental component summary score (p = 0.51).

CONCLUSIONS

Low serum cholesterol level in midlife predicted not only better survival but also better physical function and QoL in old age, without adversely affecting mental QoL.