Weight proves most influential factor on adult bone health
life than childhood factors or foetal programming, reveals a small
study from the UK.
Foetal programming and childhood factors have been associated with serious adult health risks, such as obesity, heart disease, and cancer.
But researchers who monitored the health of 171 men and 218 women born in Newcastle say that weight in adulthood overrides much of the effect on bone health that can be influenced by birthweight.
Indeed an adult's weight seemed to be the single most important factor in bone mineral density. This finding has serious implications for public health, given current rates of obesity.
In the UK, a quarter of all adults now have a body mass index (BMI) rating of more than 30, the yardstick of obesity. Other European countries are expecting to experience similar figures as the prevalence of obesity continues to rise.
The Newcastle subjects completed a detailed health and lifestyle questionnaire and underwent tests to gauge bone mineral density (BMD) of the hip, spine, and top of the thigh bone (femur).
Writing in the Journal of Epidemiology and Community Health (issue 59, pp475-80), researchers from the Royal Victoria Infirmary in Newcastle note that birthweight was a significant factor for bone size in men, and for bone mineral density in both sexes.
But all in all, these factors accounted for less than 7 per cent of the variation in BMD in men and for less than 1 per cent in women.
For both sexes, almost half of the variation in BMD explained by early childhood factors was mediated through weight in adulthood.
Vitamin C intake also seemed to be important for men. Decreasing adult vitamin C intake was a significant predictor of decreased hip bone mineral density and decreased BMD of the lumbar spine. However this association was no longer significant after adjustment for adult weight.
Overall, adult lifestyle and body size accounted for most of all the variation in the indicators of bone health at age 49-51 in both sexes.
Adult weight was a particularly important factor for women, and accounted for 25 per cent of the variation in BMD.
The authors conclude that while "birthweight does seem to influence skeletal growth, adult lifestyle and body size seem to be the most important determinants of bone health in middle age in this cohort." Cutting the risk of poor bone health in middle age means adopting a healthy lifestyle, they add.
