Association of Baseline and Longitudinal Changes in Body Composition Measures with Risk of Heart Failure and Myocardial Infarction in Type 2 Diabetes: Findings From the Look AHEAD Trial
Deliberately losing weight is associated with a lower risk of heart failure (HF) and atherosclerotic cardiovascular disease among patients with type 2 diabetes. There is less knowledge available to study the relationship between changes in body composition parameters due to weight loss and risk of heart failure (HF) and myocardial infarction (MI). Patel and colleagues (2020) published a study paper in the American Heart Association Journal titled “Association of Baseline and Longitudinal Changes in Body Composition Measures with Risk of Heart Failure and Myocardial Infarction in Type 2 Diabetes Findings from the Look AHEAD Trial”. A summary of the findings is given below:
Objective:
To validate established anthropometric prediction equations using direct measures as compared to a dual-energy x-ray absorptiometry (DXA) scan. To evaluate the association between changes in body composition with weight loss and risk of HF and MI.
Method:
Adult participants were included in the study from look AHEAD trial (Action for Health in Diabetes) without the prevalence of HF. Fat mass (FM) and lean mass (LM) were predicted using validated anthropometric prediction equations and compared with dual-energy x-ray absorptiometry (DXA) measurements in a subgroup from the Look AHEAD trial. Adjusted Cox models were used to investigate the associations of baseline and longitudinal changes in FM, LM, and WC. Participants were followed up for over 1- and 4-year to study the risk of overall HF, HF with preserved ejection fraction (EF; EF ≥50%), HF with reduced EF (EF <50%), and MI.
Findings:
The study validated the previously predicted equations with DXA measures. Levels of FM, LM, and waist circumference (WC) were directly proportional to the risk of HF. The study also adds that this proportionality is related to differences in cardiorespiratory fitness (CRF). On the other hand, a paradoxical relationship of higher FM and WC with a lower risk of MI was observed among the participants independent of potential confounders. A decrease in FM during longitudinal follow-up was found to be associated with a lower risk of HF hospitalization and its subtypes i.e., HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF). A significant reduction in risk of HF is investigated with reducing central adiposity, as measured by WC. This reduction was linked to a reduction in the risk of HFpEF but not HFrEF.
Limitations:
Investigators acknowledge the following limitations:
1) Direct measurements were not available for FM and LM in all participants, and anthropometric prediction equations were used to estimate FM and LM in the entire study population as the study observed that these measures were highly correlated to DXA-based measures.
2) Study included participants from the Look AHEAD trial who had T2DM and overweight or obese and were able to complete a maximal exercise treadmill test. Hence, findings can’t be generalized to the population.
3) Measures of regional adipose tissue depots, such as visceral adipose tissue, subcutaneous adipose tissue, and lower body fat, or measures of muscle strength, was unavailable. Hence, the effect of each of these measures on the downstream risk of HF differently is not investigated.
4) Outpatient diagnosis of HF may have been missed in the study for studying the primary outcome of HF hospitalization.
The author acknowledges future studies to evaluate if interventions preferentially targeting large, sustained losses of FM and central adiposity may be more effective in lowering the risk of HF.
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