Middelomtrek voorspelt mortaliteit onafhankelijk van BMI

Waist circumference predicts mortality irrespective of BMI 

Waist circumference is a strong risk factor for mortality in older adults, independently of body mass index (BMI), a large population study has found.

The results emphasize the importance of avoiding gains in waist circumference in people who are otherwise of healthy weight, say Eric Jacobs (American Cancer Society, Atlanta, Georgia, USA) and colleagues in the Archives of Internal Medicine.

Jacobs and team examined the association between waist circumference and mortality in the Cancer Prevention Study II Nutrition Cohort. This was a large prospective study of predominantly White adults; the median age was 69 years in men and 67 years in women.

During 9 years of follow-up, 9315 of 48,500 men and 5332 of 56,343 women died.

The researchers found that men and women in the highest category of waist circumference (≥110 cm for women and ≥120 cm for men) were more likely than those with smaller waists to be less educated, to have a high BMI, to be physically inactive, to be former smokers, and to have a history of cardiovascular disease, cancer, or respiratory disease.

Interestingly, BMI and waist circumference only moderately correlated with each other, with an age-adjusted correlation coefficient (r-value) of 0.79 in men and 0.80 in women.

After adjustment for multiple confounders (including BMI), being in the highest category of waist circumference was associated with a two-fold increased risk for mortality in both men (relative risk [RR]=2.02) and women (RR=2.36) compared with being in the lowest categories.

Furthermore, waist circumference was associated with an increased risk for mortality in all categories of BMI. In men, a 10-cm increase in waist circumference was associated with a RR of 1.16, 1.18, and 1.21 among normal-weight, overweight, and obese individuals, respectively.

In women, the respective RRs were 1.25, 1.15, and 1.13, meaning that the association was strongest in those with a normal BMI.

"Results from this large prospective study emphasize the importance of waist circumference as a risk factor for mortality in older adults, regardless of whether the BMI is categorized as normal, overweight, or obese," Jacobs et al conclude.

"Our results suggest that, regardless of weight, avoiding gains in waist circumference may reduce risk of premature mortality."

Arch Intern Med 2010; 170: 1293–1301