New indexes of body fat distribution and sex-specific risk of total and cause-specific mortality: a prospective cohort study

Abstract

BackgroundA number of prior studies have examined the association between anthropometric measures and mortality, but studies investigating the sex-specific predictive value of novel anthropometric measures on mortality are scarce so far. Therefore, we investigated the sex-specific relevance of the new anthropometric measures body adiposity index (BAI) and waist to height ratio (WHtR) as well as the common measures body mass index (BMI), waist circumference (WC), and waist to hip ratio (WHR) for cause-specific mortality risk.MethodsThe analysis was based on data from the German population based KORA (Cooperative Health Research in the Region of Augsburg) Augsburg cohort study. A total of 6670 men and 6637 women aged 25 to 74 years at baseline examination were included. During a mean follow-up period of 15.4 years, 2409 persons died. Via Cox proportional hazard regression, the associations between the different anthropometric measures and all cause-, cardiovascular disease (CVD)- and cancer mortality were assessed.ResultsBMI, WC, and WHR were significantly associated with all-cause and CVD-mortality in both sexes. WC and WHR were particularly associated with higher all-cause and CVD-mortality risk in women, while in men especially WHtR and BAI were strongly related to these outcomes. Females with WC, WHtR, and WHR measures in the 4th quartile compared with women in the 2nd quartile had a higher risk of death from cancer. Contrary, men in the lowest quartile of WC and WHtR in comparison to men in the 2nd quartile had a significantly elevated cancer mortality risk. BAI was no risk predictor for all-cause and cause-specific mortality in women.ConclusionsCentral obesity reflects higher all-cause and CVD-mortality risk particularly in women. BAI and WHtR seem to be valid as risk predictors for all-cause and especially CVD mortality in men but not women. There are marked sex-differences regarding cancer mortality risk for the different anthropometric measures.Electronic supplementary materialThe online version of this article (10.1186/s12889-018-5350-8) contains supplementary material, which is available to authorized users.

Causal relevance of obesity on the leading causes of death in women and men: A Mendelian randomization study

“…The associations with risk of CAD in men and women combined are consistent with previous studies (4,(6)(7)(8)10,11,15,17). While observational studies have indicated that waist-related traits may be more strongly associated with cardiovascular disease in women than men, they have not been conclusive (15,17,76). However, a recent study (11) investigated the effect of higher WHRadjBMI, lower gluteofemoral fat distribution, and higher abdominal fat distribution, proxied by genetic variants, on CAD and T2D risk and found no evidence that relationships differed between men and women, similar to our findings.…”

“…All obesity traits increased risk of CAD in both sexes, with no difference detected in the magnitude of effect between women and men. The associations with risk of CAD in men and women combined are consistent with previous studies (4,(6)(7)(8)10,11,15,17). While observational studies have indicated that waist-related traits may be more strongly associated with cardiovascular disease in women than men, they have not been conclusive (15,17,76).…”

“…In contrast, we found that BMI conferred a higher T2D risk in women than in men. Whereas men tend to be diagnosed with T2D at lower BMI than women (65), there may be a stronger association between increase of BMI and T2D risk in women than in men (15,18,64,(66)(67)(68)(69). Whether this reflects a stronger causal effect of BMI on T2D risk in women has hitherto been unknown.…”

“…Obesity traits are known to differ between women and men; regional obesity prevalence rates often vary between the sexes (12,13), women have higher SNP-based heritability for WHR (14), and >90% of WHRadjBMI-associated SNPs that show evidence of sexual dimorphism have larger effect sizes in women than men (14). It has been suggested that fat distribution related traits might be more strongly associated with cardiometabolic outcomes in women, although many previous studies are inconclusive (15)(16)(17)(18)(19). Only a few studies have investigated sex differences in the effect of genetic risk for obesityrelated traits on disease risk (6,9,11) and have mostly been restricted to waist-related traits and T2D and CAD, using a limited number of analyses and/or SNPs, but without finding evidence of differences in disease risk between men and women (6,9,11).…”

Relationship between endothelium-dependent vasodilation and fat distribution using the new “imiomics” image analysis technique

“…Thus, although the link between obesity and a poor endothelium-dependent vasodilation is well established the link between fat distribution and endotheliumdependent vasodilation is less well studied [14]. Abdominal fat distribution seems to be more deleterious than adipose tissue located in the hip region [15,16]. Also visceral adipose tissue (VAT) is regarded as more dangerous that subcutaneous adipose tissue (SAT) [17e19], and increased liver fat has been highlighted to be a major player in the harmful effects of obesity, although it was not related to incident CVD in the MESA study [20].…”