Late-life factors associated with healthy aging in older men

Abstract

Objectives: To identify potentially modifiable late-life biological, lifestyle, and sociodemographic factors associated with overall and healthy survival to age 85.

Design: Prospective longitudinal cohort study with 21 years of follow-up (1991-2012).

Setting: Hawaii Lifespan Study.

Participants: American men of Japanese ancestry (mean age 75.7, range 71-82) without baseline major clinical morbidity and functional impairments (N = 1,292).

Measurements: Overall survival and healthy survival (free from six major chronic diseases and without physical or cognitive impairment) to age 85. Factors were measured at late-life baseline examinations (1991-1993).

Results: Of 1,292 participants, 1,000 (77%) survived to 85 (34% healthy) and 309 (24%) to 95 (<1% healthy). Late-life factors associated with survival and healthy survival included biological (body mass index, ankle-brachial index, cognitive score, blood pressure, inflammatory markers), lifestyle (smoking, alcohol use, physical activity), and sociodemographic factors (education, marital status). Cumulative late-life baseline risk factor models demonstrated that age-standardized (at 70) probability of survival to 95 ranged from 27% (no factors) to 7% (≥ 5 factors); probability of survival to 100 ranged from 4% (no factors) to 0.1% (≥ 5 factors). Age-standardized (at 70) probability of healthy survival to 90 ranged from 4% (no factors) to 0.01% (≥ 5 factors). There were nine healthy survivors at 95 and one healthy survivor at 100.

Conclusion: Several potentially modifiable risk factors in men in late life (mean age 75.7) were associated with markedly greater probability of subsequent healthy survival and longevity.

Keywords: healthy aging; late-life; longevity; longitudinal cohort study; risk factors.

Figure 1. Age-standardized (at 70) probability of survival by number of risk factors present at baseline

The probabilities of survival are estimated assuming all 6 groups start at age 70 in the graph. All participants were Japanese American men followed from late-life baseline (1991–1993) to 2012. Survival risk score indicates the number of risk factors (unmarried, low body mass index <19 kg/m², low forced expiratory volume in 1 minute (FEV1 <2.1), high diastolic blood pressure >90mmHg, past smoker, current smoker, alcohol use >15 oz/month, low physical activity index, fewer than 12 city blocks walked/day, higher fibrinogen >351 mg/dl, higher white blood count >6000 cells/m³.

Figure 2. Age-standardized (at 70) probability of healthy survival (free of chronic disease, cognitive impairment and disability) by number of risk factors present at baseline

The probabilities of healthy survival are estimated assuming all 6 groups start at age 70 in the graph. All participants were Japanese American men followed from late-life baseline (1991–1993) to 2012. Among those alive at age 85, exceptional survival was defined as absence of 6 major chronic diseases and absence of physical and cognitive disability. Survival risk score indicates number of risk factors (education < 12years, body mass index ≥25 kg/m², systolic blood pressure >160, CASI score 74–81.9, ankle-brachial index <0.9, poor self-rated health, high fibrinogen >351 mg/dl, higher white blood count >6000 cells/m³).