Healthy survival
- Study
- Results
- Comment
Suppose
for a moment you are a man (Bandolier readers who are not will excuse us for a
moment for a little reverie). Suppose you are 55 years old and healthy. Suppose
you have developed a burning desire to:
- Make sure that you get the very last drop out of your pension fund, or
- To see Macclesfield win the European Championship (any other extremely remote sporting achievement), or
- Want to see documents about the present government released under the 30-year rule.
Whichever
you choose, you need to live for another 30 years, and since you are going to
do that, you need to remain free of physical or mental problems. This has also
been called exceptional survival, exceptional because so few actually achieve
it.
Bandolier 78 examined findings of the US Nurses' Study that showed
that women with healthy lifestyles lived far longer than those who did not. We
now have a similar finding for men [1].
Study
This
was a report of the Honolulu Heart Program, which recruited over
Japanese-American men in 1965-1968. The men were aged 45 to 68 years old
(average 54 years). In subsequent years it has followed up mortality and
development of major physical illness and cognition, during eight follow up
visits up to 2005. A physical examination was performed at baseline, as well as
biochemical and other variables.
Participants
were classified into one of four types:
- Non survivors, who died before a specified age (75, 80, 85, 90 years).
- Usual survivors but disabled with a physical or cognitive disability.
- Usual survivors with chronic disease but no disability.
- Exceptional survivors who survived to a specified age without major chronic disease or cognitive or physical impairment.
Chronic
disease of interest included coronary heart disease, stroke, cancer, COPD,
Parkinson's disease, and diabetes. Physical impairment was defined as
difficulty walking half a mile (about 800 metres).
Results
Of
8006 original participants, 5,820 were healthy at baseline, did not die within
one year, and had full baseline information including physical functioning. The
classification at age 85 years is shown in Figure 1. Only 11% of men were
exceptional survivors.
Figure 1: Percentage of men in the cohort with different outcomes by age 85 years
A
set of risk factors was created after analysis of 29 different variables at
baseline:
- Hyperglycaemia
- Hypertension
- High alcohol consumption (more than three drinks a day)
- Low education
- Overweight
- High triglyceride level
- Low grip strength
- Unmarried
In
the absence of any of these risk factors, a man aged 55 would have a high
probability of survival to age 85 years (69%), and of exceptional survival
among those alive at 85 years free of disease and cognitive impairment (55%);
the probability of being alive at a age 85 and being free of major disease was
the product of these (38%). With six or more risk factors, there was much less
likelihood of any of these outcomes (22%, 9%, and 2% respectively).
Figures
2, 3, and 4 show the results graphically. With between 1 and 5 risk factors,
the probabilities gradually declined, in a more or less linear manner. Thus for
a man aged 55 years with three risk factors, the chance of survival to 85 years
would be 50%, of being an exceptional survivor if alive at 85 years 30%, and of
being both alive and free of major disease at 85 years about 15%.
Figure 2: Probability of 55 yr man being alive at 75, 80, or 85 years, with 0 or ≥6 risk factors
Figure 3: Probability of 55 yr man being free of serious disease at 75, 80, or 85 years if alive, with 0 or ≥6 risk factors
Figure 4: Probability of 55 yr man being alive at 75, 80, or 85 years and free of serious disease, with 0 or ≥6 risk factors
Comment
The
major benefits of healthy living for men in this study were not dissimilar to
those for women in the US Nurses' Study (
Bandolier 78). In the end it all
comes down to the usual healthy living advice. Don't smoke, drink
moderately, don't be overweight, exercise, eat sensibly, and, for men,
get married (helps with all the above).
Most
of all, there is a steep relationship between both survival and being free of
major disease and the number of risk factors. In the range 0-2 risk factors,
the decline is moderate. At three or more risk factors, the decline is steep
with each additional one. The lesson is to keep them to a minimum.
Essentially
this is the Bandolier healthy living advice, available from the website. So, if
you want to know the winner of the 2035 FA Cup, Ashes, or World Series, you
know how to do it.
Reference:
- BJ Willcox et al. Midlife risk factors and healthy survival in men. JAMA 2006 296: 2343-2350.
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