Aerobic exercise, not diet, improves diastolic function in type 2 diabetes, obesity
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PHILADELPHIA — Adults with type 2 diabetes and obesity without CVD experienced dramatic metabolic improvements after a 12-week, low-calorie diet intervention but saw no change in diastolic function, which was only observed with an aerobic exercise intervention, according to data presented at the American Heart Association Scientific Sessions.
“Younger, working-age adults with type 2 diabetes and obesity already have evidence of concentric left ventricular remodeling, subclinical diastolic dysfunction and aortic stiffening,” Gaurav Gulsin, MBChB, a clinical research training fellow at the British Heart Foundation at the University of Leicester, told Healio. “Aerobic exercise training led to improvements in diastolic dysfunction, but without any significant impact on weight, blood pressure or HbA1c. Although a low-calorie diet led to dramatic reductions in weight [and] BP and led to reversal of type 2 diabetes in 83% of participants, this did not in turn lead to improvements in diastolic function. However, the diet did cause some favorable improvements in left ventricular remodeling and aortic stiffening.”
The researchers first assessed a cohort of 90 adults with type 2 diabetes and obesity but no CVD (mean age, 50 years, 59% men; mean BMI, 37 kg/m²) along with 36 controls (mean age, 50 years, 51% men; mean BMI, 24 kg/m²). Participants with type 2 diabetes were then randomly assigned 1:1:1: to a 12-week intervention with routine care (n = 30), a low-energy meal replacement diet (810 kcal/day; n = 24) or a supervised aerobic exercise program (three weekly 50-minute aerobic exercise sessions; n = 22). Participants underwent bio-anthropometric profiling and cardiac MRI at baseline and 12 weeks. The primary outcome was change in LV peak early diastolic strain rate (PEDSR) from baseline to 12 weeks.
Compared with controls, participants with type 2 diabetes had greater concentric LV remodeling (P < .001), smaller left atrium volumes (P = .021) and lower circumferential PEDSR (P = .02), Gulsin said.
Compared with the exercise arm, individuals assigned to diet lost significantly more weight (mean, –14 kg vs. –2 kg) and experienced a greater decrease in systolic BP (mean, –13 mm Hg vs. –2 mm Hg) and HbA1c (mean –0.8% vs. –0.1%), with 83% achieving diabetes remission, Gulsin said. However, participants in the diet arm saw no improvement in lower circumferential PEDSR, although researchers observed a decrease in LV mass and an increase in left atrium volumes. Additionally, longitudinal PEDSR worsened in the diet arm vs. routine care (mean change from baseline, –0.097; 95% CI, –0.173 to –0.021; P = .016), Gulsin said.
Participants in the exercise arm also experienced an improvement in lower circumferential PEDSR compared with routine care (mean change from baseline, 0.132; 97.5% CI, 0.038-0.225; P = .002), without alterations in LV remodeling.
“Given the dramatic improvements in glucometabolic profiles achieved with the low-calorie diet intervention, we were surprised that diastolic function did not improve in this arm of the trial,” Gulsin said. “Instead, our trial was positive for the primary endpoint in the exercise training arm.” – by Regina Schaffer
Reference:
Gulsin GS, et al. Abstract 171. Presented at: American Heart Association Scientific Sessions; Nov. 16-18, 2019; Philadelphia.
Disclosure: Gulsin reports no relevant financial disclosures.