So as we worry we weigh: Visible burrow system stress and visceral adiposity

A Body Shape Index (ABSI) achieves better mortality risk stratification than alternative indices of abdominal obesity: results from a large European cohort

Abdominal and general adiposity are independently associated with mortality, but there is no consensus on how best to assess abdominal adiposity. We compared the ability of alternative waist indices to complement body mass index (BMI) when assessing all-cause mortality. We used data from 352,985 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) and Cox proportional hazards models adjusted for other risk factors. During a mean follow-up of 16.1 years, 38,178 participants died. Combining in one model BMI and a strongly correlated waist index altered the association patterns with mortality, to a predominantly negative association for BMI and a stronger positive association for the waist index, while combining BMI with the uncorrelated A Body Shape Index (ABSI) preserved the association patterns. Sex-specific cohort-wide quartiles of waist indices correlated with BMI could not separate high-risk from low-risk individuals within underweight (BMI < 18.5 kg/m2) or obese (BMI ≥ 30 kg/m2) categories, while the highest quartile of ABSI separated 18-39% of the individuals within each BMI category, which had 22-55% higher risk of death. In conclusion, only a waist index independent of BMI by design, such as ABSI, complements BMI and enables efficient risk stratification, which could facilitate personalisation of screening, treatment and monitoring.

Psychosocial stress and bone loss among postmenopausal women: results from the Women’s Health Initiative

Background

Bone loss is a major public health concern with large proportions of older women experiencing osteoporotic fractures. Previous research has established a relationship between psychosocial stressors and fractures. However, few studies have investigated bone loss as an intermediary in this relationship. This study investigates whether social stress is associated with bone loss during a 6-year period in postmenopausal women.

Methods

Data from 11 020 postmenopausal women from the USA was used to examine self-reported psychosocial stress in relation to change in bone mineral density (BMD) measured at the femoral neck, lumbar spine and total hip. Linear regression models were used to examine associations between social measures of psychosocial stress (social strain, social functioning and social support) and per cent change in BMD over 6 years.

Results

High social stress was associated with decreased BMD over 6 years. After adjustment for confounders, each point higher in social strain was associated with 0.082% greater loss of femoral neck BMD, 0.108% greater loss of total hip BMD and 0.069% greater loss of lumbar spine BMD (p<0.05). Low social functioning and low social support were associated with greater decreases in femoral neck BMD, and low social functioning was associated with greater decreases in total hip BMD.

Conclusion

The findings provide evidence for an association between high social stress and greater bone loss over 6 years of follow-up. In agreement with the prior literature, the findings for social strain and social functioning suggest that poor quality of social relationships may be associated with bone loss in postmenopausal women.

Obesity associated disease risk: the role of inherent differences and location of adipose depots

Obesity and associated metabolic co-morbidities are a worldwide public health problem. Negative health outcomes associated with obesity, however, do not arise from excessive adiposity alone. Rather, deleterious outcomes of adipose tissue accumulation are a result of how adipocytes are distributed to individual regions in the body. Due to our increased understanding of the dynamic relationship that exists between specific adipose depots and disease risk, an accurate characterization of total body adiposity as well as location is required to properly evaluate a population's disease risk. Specifically, distinctive tissue depots within the body include the lower body, upper body and abdominal (deep and superficial) subcutaneous regions, as well as visceral (mesenteric and omental) regions. Upper body and visceral adipose tissues are highly associated with metabolic dysfunction and chronic disease development, whereas lower body gluteofemoral subcutaneous adipose tissue imparts protection against diet-induced metabolic derangement. Each adipose depot functions distinctly as an endocrine organ hence it has a different level of impact on health outcomes. Effluent from adipose tissue can modulate the functions of other tissues, whilst receiving differential communication from the rest of the body via central nervous system innervation, metabolites and other signaling molecules. More so, adipose depots contain a diverse reservoir of tissue-resident immune cells that play an integral part in both maintaining tissue homeostasis, as well as propagating metabolically-induced inflammation. Overall, the conceptualization of obesity and associated risks needs updating to reflect the complexities of obesity. We review adipose tissue characteristics that are linked to deleterious or beneficial adipose tissue distributions.