Body mass index and mortality in elderly men and women from general population. The experience of Cardiovascular Study in the Elderly (CASTEL).
BACKGROUND
The role of body mass index (BMI) as a factor influencing longevity of the elderly subject is still under debate.


OBJECTIVE
To evaluate at a population level whether or not BMI is a risk factor of mortality in the elderly, highlighting possible gender-related differences.


METHODS
3,282 Subjects aged 65-95 years, were recruited from an Italian general population and 12-year events were recorded. Blood tests and anthropometric measurements were performed. BMI as a continuous item was divided into quintiles and, for each quintile, adjusted hazard ratio (HR) with 95% confidence intervals for mortality was derived by classes of age and gender from Cox analysis.


RESULTS
BMI inversely predicted overall and cancer mortality in men only. Overall mortality rate was 64.7% (HR = 1.63 [1.23-2.71]) in the 1st quintile of BMI, 54.9% (1.21 [0.92-1.73]) in the 2nd, 54.1% (1.20 [0.85-1.67]) in the 3rd, 53.3% (1.04 [0.82-1.32]) in the 4th and 52.5% in the 5th; cancer mortality rate was 23.1% (HR = 2.35 [1.31-4.23]), 14.2% (HR = 1.19 [0.65-1.80]), 15.8% (HR = 1.49 [0.93-2.39]), 15.8% (HR = 1.36 [0.84-2.16]) and 13.4%, respectively. The relationship between BMI and mortality remained significant only in men aged 76 years or less. No relationship was found between BMI and coronary or cerebrovascular mortality.


CONCLUSIONS
BMI <22.7 kg/m2 does not improve survival in the elderly, while it is an independent predictor of cancer mortality in men aged <or=76 years. No prediction based on BMI is possible in women.
Mazza
Alberto
A
Department of Internal Medicine, General Hospital of Rovigo, Rovigo, Italy.
Zamboni
Sergio
S
Tikhonoff
Valérie
V
Schiavon
Laura
L
Pessina
Achille C
AC
Casiglia
Edoardo
E
D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008136:Longevity / Q000502:physiology*; D008137:Longitudinal Studies; D008297:Male; D009026:Mortality; D009369:Neoplasms / Q000401:mortality; D016016:Proportional Hazards Models; D012044:Regression Analysis; D012307:Risk Factors; D012737:Sex Factors