Z-score of the log-transformed A Body Shape Index predicts low muscle mass in population with abdominal obesity: The U.S. and Korea National Health and Nutrition Examination Survey

Differential Associations of 6 Adiposity Indices With Dementia in Older Adults: The MIND-China Study

OBJECTIVES

The cross-sectional association between late-life obesity and dementia is often explained by the obesity paradox. We assessed the potential differential associations of various adiposity indices with dementia and subtypes of dementia in rural Chinese older adults.

DESIGN

A population-based cross-sectional study.

SETTING AND PARTICIPANTS

A total of 5277 participants (age ≥60 years; 57.23% female) who were living in rural communities and were examined in March-September 2018 for MIND-China.

METHODS

We used weight, height, and waist circumference (WC) to calculate 6 adiposity indices: body mass index (BMI), waist-to-height ratio (WHtR), weight-adjusted-waist index (WWI), A Body Shape Index (ABSI), body roundness index (BRI), and Conicity Index (ConI). Dementia, Alzheimer's disease (AD), and vascular dementia (VaD) were clinically diagnosed following the international criteria. Data were analyzed with logistic regression models.

RESULTS

Of the 5277 participants, 303 were diagnosed with dementia, including 193 with AD and 99 with VaD. The multivariable-adjusted odds ratio (95% CI) of dementia associated with the highest (vs lowest) quintile of adiposity index was 2.32 (1.40-3.85) for WWI, 1.56 (1.03-2.36) for ABSI, and 1.40 (0.92-2.11) for ConI. Similarly, higher levels of these 3 adiposity indices were significantly associated with an increased likelihood of AD, whereas a higher BMI was associated with a decreased likelihood of AD. None of the 6 examined adiposity indices was significantly associated with VaD when adjusting for multiple confounders.

CONCLUSIONS AND IMPLICATIONS

The adiposity index WWI is linearly associated with the likelihood of dementia and AD. An increased WWI may be a clinical marker for the dementia syndrome and Alzheimer's dementia.

Telomere length associates with chronological age and mortality across racially diverse pulmonary fibrosis cohorts

Pulmonary fibrosis (PF) is characterized by profound scarring and poor survival. We investigated the association of leukocyte telomere length (LTL) with chronological age and mortality across racially diverse PF cohorts. LTL measurements among participants with PF stratified by race/ethnicity were assessed in relation to age and all-cause mortality, and compared to controls. Generalized linear models were used to evaluate the age-LTL relationship, Cox proportional hazards models were used for hazard ratio estimation, and the Cochran-Armitage test was used to assess quartiles of LTL. Standardized LTL shortened with increasing chronological age; this association in controls was strengthened in PF (R = -0.28; P < 0.0001). In PF, age- and sex-adjusted LTL below the median consistently predicted worse mortality across all racial groups (White, HR = 2.21, 95% CI = 1.79-2.72; Black, HR = 2.22, 95% CI = 1.05-4.66; Hispanic, HR = 3.40, 95% CI = 1.88-6.14; and Asian, HR = 2.11, 95% CI = 0.55-8.23). LTL associates uniformly with chronological age and is a biomarker predictive of mortality in PF across racial groups.

Association of Body Shape Index with Cerebral Small Vessel Disease

INTRODUCTION

A body shape index (ABSI) is an anthropometric index designed to reflect the influence of visceral fat. ABSI has been previously associated with various atherosclerosis, metabolic diseases, and cardiovascular diseases; however, relatively few studies have been conducted on cerebrovascular disease. In this study, we evaluated the association between ABSI and cerebral small vessel disease (cSVD) in health check-up participants.

METHODS

We evaluated consecutive health check-up participants between January 2006 and December 2013. As subtypes of cSVD, we quantitatively measured the volume of white matter hyperintensity (WMH) and qualitatively measured the presence of silent brain infarct (SBI) and cerebral microbleed (CMB). ABSI was calculated according to the following formula: ABSI (m11/6/kg-2/3) = waist circumference (m)/(body mass index [kg/m2]2/3 × height [m]1/2).

RESULTS

A total of 3,219 health check-up participants were assessed (median age, 56 years; male sex, 54.0%). In the multivariable analysis, ABSI was significantly associated with WMH volume (β = 0.107, 95% confidence interval [CI] = 0.013-0.200), SBI (adjusted odds ratio [aOR] = 1.62, 95% CI = 1.14-2.31), and CMB (aOR = 1.64, 95% CI = 1.16-2.33) after adjusting for confounders (per 100 m11/6/kg-2/3). Furthermore, ABSI showed a dose-response relationship with the burden of each cSVD pathology.

CONCLUSIONS

High ABSI was associated with a higher burden of cSVD in health check-up participants. As ABSI showed close associations with all subtypes of cSVD, visceral fat may be a common risk factor penetrating cSVD pathologies.

Associations of Body-Roundness Index and Sarcopenia with Cardiovascular Disease among Middle-Aged and Older Adults: Findings from CHARLS

OBJECTIVES

Sarcopenia and obesity may contribute to chronic disease. However, little is known about the association between sarcopenia, body roundness index (BRI), and cardiovascular disease (CVD). The aim of this study was to investigate the association of sarcopenia and BRI with CVD in middle-aged and older Chinese population.

DESIGN

Cohort study with an 8-year follow-up.

SETTING AND PARTICIPANTS

Data were derived from 4 waves of the China Health and Retirement Longitudinal Study, and 6152 participants aged 45 or above were included in the study.

METHODS

Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. CVD was defined as the presence of physician-diagnosed heart disease, diabetes and/or stroke. The associations of BRI and sarcopenia with CVD risk were explored using Cox proportional hazards regression models.

RESULTS

The mean age of the participants was 58.3 (8.9) years, and 2936 (47.7%) were males. During the 8 years follow-up, 2385 cases (38.8%) with incident CVD were identified. Longitudinal results demonstrated that compared to neither sarcopenia or high BRI, both sarcopenia and high BRI (HR: 1.49, 95%CI: 1.08, 2.07) were associated with higher risk of CVD. In the subgroup analysis, individuals with both sarcopenia and high BRI were more likely to have new onset stroke (HR: 1.93, 95%CI: 1.12, 3.32) and increased risk of multimorbidity (HR: 2.15, 95% CI: 1.14, 4.04).

CONCLUSIONS

Coexistence of sarcopenia and high BRI was associated with higher risk of CVD. Early identification and intervention for sarcopenia and BRI not only allows the implementation of therapeutic strategies, but also provides an opportunity to mitigate the risk of developing CVD.

Implication of diet and exercise on the management of age‐related sarcopenic obesity in Asians

The incidence of sarcopenic obesity among adults aged ≥65 years is rising worldwide. Sarcopenic obesity is a high‐risk geriatric syndrome defined as a gain in the amount of adipose tissue along with the age‐related loss of muscle mass and strength or physical performance. Sarcopenic obesity is associated with increased risks of falls, physical limitations, cardiovascular diseases, metabolic diseases, and/or mortality. Thus, the identification of preventive and treatment strategies against sarcopenic obesity is important for healthy aging. Diet and exercise are the reasons for the development of sarcopenic obesity and are key targets in its prevention and treatment. Regarding weight reduction alone, it is most effective to maintain a negative energy balance with dietary calorie restriction and aerobic exercise. However, it is important to preserve skeletal muscle mass while reducing fat mass. Resistance exercise and appropriate protein supply are the main ways of preserving skeletal muscle mass, as well as muscle function. Therefore, in order to improve sarcopenic obesity, a complex treatment strategy is needed to limit energy ingestion with proper nutrition and to increase multimodal exercises. In this review, we focus on recently updated interventions for diet and exercise and potential future management strategies for Asian individuals with aging‐related sarcopenic obesity. Geriatr Gerontol Int 2022; 22: 695–704.

Association between body shape index and risk of mortality in the United States

The body mass index (BMI) neither differentiates fat from lean mass nor does it consider adipose tissue distribution. In contrast, the recently introduced z-score of the log-transformed A Body Shape Index (LBSIZ) can be applied to measure obesity using waist circumference (WC), height, and weight. We aimed to investigate the association between LBSIZ and mortality. We used data from the National Health and Nutrition Examination Survey 1999–2014 and linked the primary dataset to death certificate data from the National Death Index with mortality follow-up through December 31, 2015. A multiple Cox regression analysis was performed to evaluate the hazard ratio (HR) of all-cause and cardiovascular disease (CVD) mortalities with adjustment for baseline characteristics. LBSIZ, WC, and BMI showed positive association with total fat percentage (P < 0.001); however, only WC and BMI were positively associated with appendicular skeletal mass index (ASMI) (P < 0.001). In the multiple Cox regression analysis, only LBSIZ showed a significant HR for all-cause and CVD mortalities. Under restricted cubic spline regression, mortality risk increased with LBSIZ. However, BMI and WC showed a U-shape association. In conclusion, LBSIZ is strongly associated with all-cause and CVD mortalities. Since LBSIZ is independent of BMI, LBSIZ complements BMI to identify high-risk groups for mortality even in individuals with low or normal BMI.

Association of X-ray Absorptiometry Body Composition Measurements with Basic Anthropometrics and Mortality Hazard

Dual-energy X-ray absorptiometry (DEXA) is a non-invasive imaging modality that can estimate whole-body and regional composition in terms of fat, lean, and bone mass. We examined the ability of DEXA body composition measures (whole-body, trunk, and limb fat mass and fat-free mass) to predict mortality in conjunction with basic body measures (anthropometrics), expressed using body mass index (BMI) and a body shape index (ABSI). We used data from the 1999-2006 United States National Health and Nutrition Examination Survey (NHANES), with mortality follow-up to 2015. We found that all DEXA-measured masses were highly correlated with each other and with ABSI and that adjustment for BMI and ABSI reduced these dependencies. Whole-body composition did not substantially improve mortality prediction compared to basic anthropometrics alone, but regional composition did, with high trunk fat-free mass and low limb fat-free mass both associated with elevated mortality risk. These findings illustrate how DEXA body composition could guide health assessment in conjunction with the more widely employed simple anthropometrics.