For women with obesity, gestational diabetes may not be directly caused by energy imbalance during the second trimester, according to findings published in Cell Metabolism.
Leanne M. Redman
“There have been numerous randomized controlled trials testing various lifestyle modification approaches for preventing gestational diabetes development,” Leanne M. Redman, PhD, FTOS, a professor of clinical sciences at LSU’s Pennington Biomedical Research Center in Baton Rouge, Louisiana, told Endocrine Today. “Women with overweight or obesity are most often targeted since they are in one of the high-risk groups. Interestingly, these trials in more than 5,000 patients have been largely ineffective. Now with rigorous methods to capture what is happening to energy intake and energy expenditure, we have preliminary data to explain why this is the case.”
Redman and colleagues conducted a prospective, observational study at Pennington Biomedical Researcher Center with 62 women with obesity (BMI > 30 kg/m2) and a confirmed singleton pregnancy who were recruited from private practice OB-GYNs. Researchers compared energy intake, energy expenditure, weight gain and changes in body composition between those who developed gestational diabetes and those who did not.
Outcomes were measured at 13 to 16 weeks of gestation and again at 24 to 27 weeks of gestation. Researchers used the energy intake-balance method to calculate energy intake as the sum of total daily energy expenditure (determined from doubly labeled water) and the change in body energy stores. Macronutrient composition was used to measure diet quality, and physical activity was determined by an accelerometer worn on the wrist.
During the study period, nine women developed gestational diabetes (mean age, 29.7 years) and 53 did not (mean age, 27.4 years). The researchers found that energy intake in women with gestational diabetes (2,744 kcal per day) was similar to that of the rest of the cohort (2,606 kcal per day). Little difference was observed in caloric expenditure (gestational diabetes group: 2,855 kcal per day; control group: 2,631 kcal per day), energy balance (gestational diabetes group: 16 kcal per day; control group: 84 kcal per day), diet macronutrient composition, physical activity or weight gain.
“Gestational diabetes is thought to be similar to type 2 diabetes in that lifestyle factors, such as low levels of physical activity and a poor-quality diet with high amounts of added sugar, are linked to its development. As such, lifestyle change is considered the superior approach for prevention and treatment of gestational diabetes,” Redman said. “It was surprising to learn that for women with obesity, lifestyle-related factors attributing to early weight gain (diet and exercise) were not different between women who developed gestational diabetes and those who did not.”
Although no differences were found in most of the study’s outcomes, the researchers noted some disparities between the women who developed gestational diabetes and those who did not. More specifically, the women with gestational diabetes had more visceral adipose tissue (P = .001), weighed more and had greater fat mass, although the latter two measures were not significant. In addition, women with gestational diabetes were more likely to have relatives with diabetes (P = .004) and have higher fasting glucose (P < .001) and HbA1c (P = .04) levels as well as a fourfold higher prevalence of prediabetes.
“Our research pinpoints classical type 2 diabetes risk factors, such as higher blood sugar, HbA1c levels and insulin resistance, as early indicators of gestational diabetes management,” Redman said. “Clinical practice would be advanced by earlier evaluation of such risk factors in patients considered high risk, such as those with obesity prior to pregnancy.” – by Phil Neuffer
Disclosure: Redman reports no relevant financial disclosures.