Age- and Sex-Related Differential Associations between Body Composition and Diabetes Mellitus

Low skeletal muscle mass Accompanied by Abdominal Obesity Additively Increases the Risk of Incident Type 2 Diabetes

CONTEXT

Low skeletal muscle mass often accompanies abdominal obesity in the aging process.

OBJECTIVE

We aimed to investigate the effect of reduced skeletal muscle mass and its interaction with abdominal obesity on incident type 2 diabetes.

METHODS

This retrospective longitudinal study included a total of 36,304 diabetes-free Koreans who underwent two or more health check-ups annually or biennially. Appendicular skeletal muscle mass was measured by bioelectrical impedance analysis and was presented as a skeletal muscle mass index (SMI) adjusted for body weight. Pre-sarcopenia was defined as an SMI <1 standard deviation of the sex-specific mean for a healthy young reference group. Abdominal obesity was defined using waist circumference ≥ 90 cm for men and ≥ 85 cm for women. Participants were classified into four groups of normal, pre-sarcopenia alone, abdominal obesity alone, and pre-sarcopenic obesity according to initial body composition.

RESULTS

The cumulative incidence of diabetes was 9.1% during the 7-year follow-up. Compared with the highest tertile, the lowest sex-specific SMI tertile was significantly associated with a greater risk of incident type 2 diabetes (adjusted hazard ratio [HR] = 1.31, 95% confidence interval [CI] 1.18-1.45) in a fully adjusted model. Pre-sarcopenic obesity significantly increased incident diabetes risk (adjusted HR = 1.57, 95% CI 1.42-1.73) compared with normal body composition, pre-sarcopenia alone, or abdominal obesity alone.

CONCLUSIONS

Low skeletal muscle mass and its coexistence with abdominal obesity additively increased the risk of incident type 2 diabetes independent of the glycometabolic parameters.

Is imaging-based muscle quantity associated with risk of diabetes? A meta-analysis of cohort studies

AIMS

Greater muscle quantity (muscle mass and area) is associated with better glycemic control in adults, but its longitudinal association with risk of diabetes remains debatable. We therefore conducted this meta-analysis to address this issue.

METHODS

We performed a literature search and included cohort studies that measured muscle quantity objectively by imaging-based approaches and reported their association with risk of diabetes. Study-specific data were pooled using a random-effects model.

RESULTS

Thirty-three unique datasets, with 10 on total muscle quantity, and 23 on regional (8 on appendicular, 4 on leg, 6 on thigh, and 5 on abdominal) muscle quantity, were included. Muscle quantity was all measured by dual energy x-ray absorptiometry or computed tomography. Most datasets revealed nonsignificant outcomes. Meta-analysis showed collectively that the risk of diabetes was not related to total or regional muscle quantity in either normalized or unnormalized form, with the hazard ratios ranged from 0.92 to 1.09 per every 1 standard deviation higher of corresponding muscle quantity in general (all P > 0.10). Neither sex nor weight status affected the relationship.

CONCLUSIONS

Our study did not provide adequate evidence to support the concept that large muscle quantity was associated with low risk of diabetes in population-based cohort studies.

Whole and segmental body composition changes during mid-follicular and mid-luteal phases of the menstrual cycle in recreationally active young women

BACKGROUND

Changes in oestradiol and progesterone hormones and associated fluid retention during the menstrual cycle phases might affect body composition (BC) in women.

AIM

The main objectives of this study were to determine the changes in whole and segmental BC by dual-energy x-ray absorptiometry (DXA) and bioelectrical impedance (BIA) during the mid-follicular (MFP) and mid-luteal (MLP) phases.

SUBJECTS AND METHODS

Thirty recreationally active young women participated in this study. BC was measured by DXA and BIA during MFP and MLP. A mixed linear model for repeated measures analysis was used to determine the differences between the two phases.

RESULTS

Body mass was higher during MLP than MFP, while total body water, total and segmental fat mass and fat percentages measured by both BIA and DXA were similar during the two phases. DXA-derived fat-free mass and soft lean mass in the android region were higher during MLP than MFP. Large variability in individual responses was evident.

CONCLUSION

On average, whole and segmental BC variables do not change significantly between MFP and MLP. However, given the large variability among the individual responses, it is suggested to perform repeated BC measurements during the same phase of the menstrual cycle.