Becky McCall
January 27, 2014
Risk for type 2 diabetes is shared, with around a 20% increased risk for individuals whose partners have the disease, confirms a new study, whose authors suggest that behavioral and environmental factors might have a significant role to play.
Findings of the systematic review and meta-analysis are published online January 24 in BMC Medicine.
“If you diagnose diabetes in one spouse, consider evaluating the other,” senior author Kaberi Dasgupta, MD, from McGill University Health Centre (MUHC), Montreal, Quebec, toldMedscape Medical News in an interview. “If possible, work with both members of the couple to achieve optimal diabetes management. They may be able to support each other.”
Family history of diabetes usually refers to biological relatives, and there is an underlying assumption that genetic programming is the most significant determinant of the disease. But looking into the influence of socioenvironmental factors, Dr. Dasgupta and her colleagues investigated the possibility that individuals may have a similar type 2 diabetes risk to other family members because of shared dietary habits and/or physical-activity patterns.
Dr. Dasgupta explained that the studies included in their meta-analysis did not all systematically collect data on socioenvironmental factors. “It is reasonable to assume, however, that the shared risk was driven by socioenvironmental factors, given that couples are not biologically related,” she observed.
Type 2 Diabetes Risk Increased by 20% to 25% in Partners
To determine the effect of nongenetic factors in partners of those already diagnosed with type 2 diabetes, the researchers analyzed data from 6 cross-sectional, case-control, and cohort studies examining spousal association for diabetes and/or prediabetes using records from 1997 to 2013. Odds ratios and incidence-rate ratios with body mass index (BMI) adjustment were pooled separately from those without BMI adjustment, to distinguish effects where BMI was a factor compared with effects independent of BMI.
Analysis of data drawn from 75,498 couples showed the risk for type 2 diabetes was indeed shared. “There is a 26% risk increase for diabetes if your partner has it,” Dr. Dasgupta pointed out.
The method of assessment of type 2 diabetes also had some bearing on levels of association, she noted. For example, one study in which participants performed blood tests on themselves “suggested that the risk was doubled if your partner has diabetes.”
Specifically, concordance between spousal diabetes and partner risk was lowest in a study that relied on women’s reports of diabetes, whether in themselves or their spouses (effect estimate, 1.1) and highest in a study with systematic assessment of glucose tolerance (effect estimate, 2.11).
Before adjustment for BMI, the pooled estimate suggested that a spousal history of diabetes was associated with a 26% risk increase for diabetes overall (effect estimate, 1.26). Upon adjustment for BMI, this dropped to 18% (effect estimate, 1.18).
“The fact that adjustment for BMI did not eliminate the difference, however, suggests that other factors may also be important such as physical activity, types of food consumed, etc,” remarked Dr. Dasgupta.
Implications for Prevention and Early Detection
Dr. Dasgupta said the new findings should spur prevention efforts and might also motivate families to work together toward diabetes prevention.
“This association could make patients, healthcare practitioners, and policy makers place [greater] emphasis on helping to change behaviors and environments to facilitate…change for diabetes prevention,” she suggested.
However, more work will be needed to determine the cost-effectiveness of careful assessment and evaluation of the spouses of people diagnosed with diabetes, she said, noting that this was not addressed in the current study.
“There is no such routine assessment of spouses of which I am aware. I suspect, however, that in ‘old-style’ family-medicine practices, if entire families are truly followed by a healthcare practitioner, discovery of diabetes in one family member may stimulate evaluation in others.”
Furthermore, Dr. Dasgupta added that men are less likely than women to undergo regular medical evaluation after childhood and that might contribute to delayed diabetes detection, so following male spouses more closely might be particularly beneficial in these cases.
The authors have reported no relevant financial relationships.
BMC Med. Published online January 24, 2014. Article