Food Intake Gene Is Clue to Diabetes Susceptibility

Interactions with a genetic variant involved in regulating food intake may play a role in how body mass index (BMI) affects patients’ susceptibility to diabetes mellitus (DM), according to the results of a new study.

“Our study emphasizes that reducing total energy intake might be an effective strategy for obesity prevention, particularly in children and adolescents with a high genetic risk of obesity,” Qibin Qi, PhD, Assistant Professor, Department of Epidemiology & Population Health, Albert Einstein College of Medicine in New York, told ConsultantLive.

FTO, the strongest known genetic susceptibility gene for adiposity, is associated with type 2 DM. “It has been suggested that FTO might be involved in regulating food intake,” Dr Qi told the American Diabetes Association 74^th Scientific Sessions in San Francisco. “We aimed to examine the association between the FTO-rs9939609 variant (or a proxy single-nucleotide polymorphism) and total energy and macronutrient intake and dietary intakes on BMI in children and adolescents.”

Dr Qi and colleagues performed a meta-analysis based on data from more than 16,000 boys and girls aged 3 to 18 years from 15 studies (Abstract 382-OR). Dietary intakes were assessed by food frequency questionnaires, dietary records, or 24-hour recalls. Macronutrient intake was expressed as a percentage of total energy intake.

The minor allele of the FTO-rs9939609 variant was associated with higher BMI and total energy intake but was not associated with dietary protein, carbohydrate, or fat intake. “We also found a significant interaction between the FTO variant and protein intake on BMI,” Dr Qi said. The association between the FTO variant and BMI was much stronger among those with high protein intake than those with low intake.

“The FTO variant that confers a predisposition to higher BMI may accentuate the association between the FTO variant and adiposity in children and adolescents,” Dr Qi said. More studies are needed to examine the role of FTO in the relationships among dietary intake, obesity, and type 2 DM.

The researchers did not find an association between FTO and macronutrients, suggesting that FTO might not be involved in food preference but has an influence on total food intake, Dr Qi said. The data support previous findings that FTO may play a key role in food intake, but the mechanisms by which FTO regulate food intake are unclear, he noted.

The researchers do not know how the interaction affects the susceptibility to DM, but “as BMI is a major risk factor for diabetes, it is plausible that individuals carrying the risk of the FTO allele might be more susceptible to diabetes, especially with high dietary protein intake,” Dr Qi said.

Control of body weight is the most important factor in reducing the future risk of DM. “Children or adolescents genetically predisposed to obesity (those who have a family history of obesity or are FTO risk allele carriers) might need to pay more attention to body weight to prevent obesity and diabetes,” Dr Qi stated.