Studies identify modifiable factors associated with exceptionally long life

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Studies identify modifiable factors associated with exceptionally long

life

A healthy lifestyle during the early elderly years—including weight

management, exercising regularly and not smoking—may be associated

with a greater probability of living to age 90 in men, as well as good

health and physical function, according to a report in the February 11

issue of Archives of Internal Medicine, one of the JAMA/Archives

journals. A second article in the same issue finds that although some

individuals survive to 100 years or beyond by avoiding chronic

diseases, other centenarians live with such conditions for many years

without becoming disabled.

Studies of twins have found that about one-fourth of the variation in

human life span can be attributed to genetics, according to background

information in the article. That leaves about 75 percent that could be

attributed to modifiable risk factors.

Laurel B. Yates, M.D., M.P.H., of Brigham & Women's Hospital, Boston,

and colleagues studied a group of 2,357 men who were participants in

the Physician's Health Study. At the beginning of the study, in 1981

to 1984, the men (average age 72) provided information about

demographic and health variables, including height, weight, blood

pressure and cholesterol levels and how often they exercised. Twice

during the first year and then once each following year through 2006,

they completed a questionnaire asking about changes in habits, health

status or ability to do daily tasks.

A total of 970 men (41 percent) lived to age 90 or older. Several

modifiable biological and behavioral factors were associated with

survival to this exceptional age. " Smoking, diabetes, obesity and

hypertension significantly reduced the likelihood of a 90-year life

span, while regular vigorous exercise substantially improved it, " the

authors write. " Furthermore, men with a life span of 90 or more years

also had better physical function, mental well-being, and

self-perceived health in late life compared with men who died at a

younger age. Adverse factors associated with reduced

longevity—smoking, obesity and sedentary lifestyle—also were

significantly associated with poorer functional status in elderly years. "

The researchers estimate that a 70-year-old man who did not smoke and

had normal blood pressure and weight, no diabetes and exercised two to

four times per week had a 54 percent probability of living to age 90.

However, if he had adverse factors, his probability of living to age

90 was reduced to the following amount:

* Sedentary lifestyle, 44 percent

* Hypertension (high blood pressure), 36 percent

* Obesity, 26 percent

* Smoking, 22 percent

* Three factors, such as sedentary lifestyle, obesity and

diabetes, 14 percent

* Five factors, 4 percent

" Although the impact of certain midlife mortality [death] risks in

elderly years is controversial, our study suggests that many remain

important, at least among men, " the authors conclude. " Thus, our

results suggest that healthy lifestyle and risk management should be

continued in elderly years to reduce mortality and disability. "

In the second study, Dellara F. Terry, M.D., M.P.H., of the Boston

University School of Medicine and Boston Medical Center, and

colleagues studied 523 women and 216 men age 97 or older. These

centenarians completed questionnaires about their health history and

functional ability by mail or telephone. Participants were split into

groups based on sex and the age at which they developed diseases

typically associated with aging: chronic obstructive pulmonary

disease, dementia, diabetes, heart disease, hypertension,

osteoporosis, Parkinson's disease and stroke. Those who developed

these conditions at age 85 or older were classified as delayers,

whereas those who developed them at a younger age were termed survivors.

Of the participants, 32 percent were survivors and 68 percent were

delayers— " thus, morbidity [illness] was not compressed toward the end

of these exceptionally long life spans, " the authors write. " Yet,

centenarians who had developed heart disease and/or hypertension

before age 85 years and still survived to 100 years demonstrated

similar levels of function (`independent' in the case of men and

`requires minimal assistance' in the case of women) as those who

delayed morbidity until after age 85 years. "

Though fewer men than women survive to extremely old age, the male

centenarians in this study appeared to have better mental and physical

function than their female counterparts. " One explanation for this may

be that men must be in excellent health and/or functionally

independent to achieve such extreme old age, " the authors write.

" Women on the other hand may be better physically and socially adept

at living with chronic and often disabling health conditions. "

The results regarding the timing of illness in centenarians " may shed

additional light on the various ways in which people can survive to

extreme old age, " the authors conclude. " Determining the mechanisms

that facilitate the delay or escape of disability in the face of

clinically evident age- and mortality-associated morbidities merits

further investigation. "

(Arch Intern Med. 2008;168[3]:284-290, 277-283. Available pre-embargo

to the media at www.jamamedia.org.)

Archives of Internal Medicine, Vol. 168 No. 3, February 11, 2008:

Exceptional Longevity in Men

Modifiable Factors Associated With Survival and Function to Age 90 Years

Laurel B. Yates, MD, MPH; Luc Djoussé, MD, MPH, DSc; Tobias Kurth, MD,

ScD; E. Buring, ScD; J. Gaziano, MD, MPH

Arch Intern Med. 2008;168(3):284-290.

Background Prospective data on nongenetic determinants of exceptional

longevity are limited, and information on long-lived men and their

functional status is particularly sparse. We examined modifiable

factors associated with a life span of 90 or more years and late-life

function in men.

Methods In this prospective cohort study of 2357 healthy men (mean

age, 72 years) within the Physicians' Health Study (1981-2006),

biological and lifestyle factors and comorbid conditions were assessed

by self-report with baseline and annual questionnaires. Mortality and

incidence of major diseases were confirmed by medical record review.

Late-life function was assessed 16 years after baseline by the Medical

Outcomes Study 36-Item Short-Form Health Survey.

Results A total of 970 men (41%) survived to at least age 90 years.

Smoking was associated with increased risk of mortality before age 90

years (hazard ratio

---

; 2.10; 95% confidence interval [CI],

1.75-2.51), and similar associations were observed with diabetes (HR,

1.86; 95% CI, 1.52-2.26), obesity (HR, 1.44; 95% CI, 1.10-1.90), and

hypertension (HR, 1.28; 95% CI, 1.15-1.43). Regular exercise was

associated with a nearly 30% lower mortality risk (HR, 0.72; 95% CI,

0.62-0.83). The probability of a 90-year life span at age 70 years was

54% in the absence of smoking, diabetes, obesity, hypertension, or

sedentary lifestyle. It ranged from 36% to 22% with 2 adverse factors

and was negligible (4%) with 5. Compared with nonsurvivors, men with

exceptional longevity had a healthier lifestyle (67% vs 53% had & #8804;1

adverse factor), had a lower incidence of chronic diseases, and were 3

to 5 years older at disease onset. They had better late-life physical

function (mean ± SD score [maximum 100], 73 ± 23 vs 62 ± 30; P < .001)

and mental well-being (mean score, 84 ± 14 vs 81 ± 17; P = .03). More

than 68% (vs 45%) rated their late-life health as excellent or very

good, and less than 8% (vs 22%) reported fair or poor health (P < .001

for trend). Regular exercise was associated with significantly

better—and smoking and overweight with significantly worse—late-life

physical function. Smoking also was associated with a significant

decrement in mental function.

Conclusion Modifiable healthy behaviors during early elderly years,

including smoking abstinence, weight management, blood pressure

control, and regular exercise, are associated not only with enhanced

life span in men but also with good health and function during older age.