Couples may share risks for type 2 diabetes, obesity

Among middle-aged adults, a man is more likely to develop type 2 diabetes if his wife has obesity, and both men and women are more likely to develop obesity if their spouse has diabetes, according to findings from two studies presented at the European Association for the Study of Diabetes Annual Meeting.

Increased diabetes risk

The researchers found no statistically significant indication overall that having a spouse with diabetes increases diabetes risk. However, further analysis showed that a man’s risk for developing type 2 diabetes during follow-up rose by 21% for each 5 kg/m² increase in his wife’s BMI, after adjusting for the man’s BMI.

“Having an obese wife increases a man's risk for diabetes over and above the effect of his own obesity level, while among women, having an obese husband gives no additional diabetes risk beyond that of her own obesity level,” Adam Hulman, MSc, PhD, of the departments of public health and epidemiology at Aarhus University in Denmark, and colleagues wrote in an abstract presenting the findings. “Our results indicate that on finding obesity in a person, screening of their spouse for diabetes may be justified.”

Hulman and colleagues analyzed data from 3,151 men and 3,050 women without diabetes at baseline who participated in the English Longitudinal Study of Ageing (ELSA), a representative cohort of the English population aged at least 50 years. Participants were interviewed every 2.5 years between 1998 and 2015. Type 2 diabetes incidence was based on clinical examinations conducted during waves 2, 4 and 6, and was determined by screen-detected HbA1c of at least 6.5% or fasting plasma glucose of at least 7 mmol/L, or self-reported diagnosis on a questionnaire.

Researchers used Cox proportional hazards models to determine HRs for developing type 2 diabetes, using spousal diabetes status or obesity (determined by BMI and waist circumference) as exposures. The effects of continuous exposures were modeled using splines to reveal potential nonlinearity.

Researchers found that women were more likely than men to have a spouse with diabetes at baseline (6.4% vs. 3.3%). Incidence of diabetes was 12.6 per 1,000 person-years among men and 8.6 per 1,000 person-years among women.

A woman with a husband with diabetes had a higher risk for developing the disease (HR = 1.45; 95% CI, 0.97-2.19); however, researchers did not observe this trend in men with a wife who had diabetes. The association between waist circumference and diabetes risk exhibited a similar pattern, they noted.

Among both men and women, having a spouse with obesity was associated with an increased risk for developing type 2 diabetes; however, this association was attenuated for women after adjustment for a woman's BMI. Among men, the associations remained statistically significant.

Increased obesity risk

In a separate study analyzing obesity development among adults with a spouse with or without type 2 diabetes, Hulman and colleagues assessed age-related trajectories of BMI from 7,187 men and women in opposite-sex marriages from the ELSA cohort, using mixed-effects models. The researchers found that among adults aged at least 55 years, living with a spouse with type 2 diabetes was associated with higher levels of obesity compared with adults with a spouse without diabetes.

Researchers did not observe between-group differences for BMI at age 50 years among adults with spouses with and without diabetes; across all groups, BMI increased with age until age 70 years, before declining slightly. However, among men with a wife with diabetes, researchers observed a steeper increase in BMI when compared with men with a spouse without diabetes up to age 60 years, whereas women with a spouse with diabetes had a similar BMI trajectory to that of women who did not have a spouse with diabetes, but their average BMI levels were higher.

Among men and women, those with a spouse with type 2 diabetes had a higher waist circumference throughout follow-up compared with those with a spouse without diabetes, according to researchers, but the difference was statistically significant only in women.

“Women with a spouse with diabetes had a similar BMI trajectory to women who did not have a spouse with diabetes, but their average BMI levels were higher,” the researchers wrote. “We observed similar shapes in waist circumference trajectories by spousal diabetes status for men and women.”

The researchers added that recognizing “shared risk” between spouses may improve diabetes detection and motivate couples to increase collaborative efforts to eat more healthily and boost their activity levels.

“Obesity or [type 2 diabetes] in one spouse may serve as a prompt for diabetes screening and regular weight checks in the other,” the researchers wrote. “In particular, men whose wives are obese may benefit from being followed more closely.” – by Regina Schaffer

Reference:

Hulman A, et al. Abstracts 80 and 308. Presented at: European Association for the Study of Diabetes Annual Meeting; Sept. 11-15, 2017; Lisbon, Portugal.

Disclosures: The Danish Diabetes Academy, funded by the Novo Nordisk Foundation, supported this study. The authors report no relevant financial disclosures.