Sugar-sweetened Beverages Associated With Insulin Resistance and Prediabetes

Regular sugar-sweetened beverage (SSB) intake, but not diet soda consumption, is associated with a greater increase in insulin resistance and a higher risk of developing prediabetes, according to a new study.

“This is one of the few observational studies to look at the long-term relationship between SSB intake and the incidence of prediabetes, so it’s filling a gap in the research,” said study author Nicola McKeown, PhD, a scientist in the nutritional epidemiology program at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston. “While previous observational studies focused on the association between SSB and type 2 diabetes, our study focused on prediabetes.”

Researchers analyzed the prospective association between cumulative mean consumption of SSBs or diet soda and incident prediabetes (n=1685) identified across a median of 14 years of follow-up in participants [mean ± SD age: 51.9 ± 9.2 years; 59.6% women; mean ± SD body mass index (BMI; kg/m²): 26.3 ± 4.4] of the Framingham Offspring cohort. They also analyzed the prospective association between beverage consumption and change in homeostasis model assessment of insulin resistance (HOMA-IR; n=2076) over approximately 7 years. The investigators estimated cumulative mean consumption of SSBs and diet soda by using food-frequency questionnaires. They implemented multivariable Cox proportional hazards models and linear regression models to estimate the HRs of incident prediabetes and change in HOMA-IR, respectively.

After adjustment for multiple potential confounders, including baseline BMI, they observed SSB intake to be positively associated with incident prediabetes (P-trend<0.001); the highest SSB consumers (>3 servings/week; median: 6 servings/week) had a 46% higher risk of developing prediabetes than did the SSB nonconsumers (HR: 1.46; 95% CI: 1.16, 1.83). Higher SSB intake also was associated with a greater increase in HOMA-IR (P-trend=0.006). They observed no prospective associations between diet soda intake and risk of prediabetes (P-trend=0.24) or changes in HOMA-IR (P-trend=0.25). These associations were similar after additional adjustment for change in BMI.

For future work, the investigators are collaborating with a number of cohort studies to examine the relationship between SSB intake and measures of glucose and insulin metabolism, and they’re expanding the research to examine whether SSB consumption increases a person’s diabetes risk differently, depending on his or her genetic makeup.

“Basically, we want to consider the fact that everyone has a unique set of genes that may be related to how SSB are broken down in the body,” Dr McKeown said. “To do this, we are looking at a number of genes that have been shown to influence the breakdown of sugars in the liver and testing whether variations in these genes could change the way consumption of SSB is related to fasting glucose and insulin levels in different individuals.”

—Mike Bederka

Reference:

Ma J, Jacques PF, Meigs JB, et al. Sugar-sweetened beverage but not diet soda consumption is positively associated with progression of insulin resistance and prediabetes [published online Nov. 9, 2016]. J Nutr. doi: 10.3945/​jn.116.234047.