Feb. 7, 2023 -- Living with a spouse or a partner may help middle-age and older adults keep their blood sugar level in check, new research suggests.
And it doesn't even have to be an ideal union. Just having the relationship seems to provide benefit, whether the partners described it as supportive or strained.
Katherine J. Ford, PhD, with the Department of Psychology at Carleton University in Ontario, Canada, led the study, published online today in the journal BMJ Open Diabetes Research & Care.
The team used data from 2004 to 2013 from more than 3,000 people in the English Longitudinal Study of Ageing (ELSA), a sample of adults in England ages 50-89 and their partners.
The people studied had not been diagnosed with diabetes and were asked over a decade about whether they had a wife, husband, or partner and whether there had been a change in their partnership status.
Ford says they saw an improvement – an average 0.2% decrease in HbA1c, a measure of average blood sugar concentrations over 3 months -- when participants transitioned into a marriage or domestic partnership and a worsening, in this case a 0.2% increase in HbA1c, when they left such a relationship.
To put the results into some context, the researchers say that other work has suggested that a decrease of 0.2% in the average HbA1c value "would decrease excess mortality by 25%.”
Potential Reasons for Benefit
So why might marriage status affect blood sugar?
Ford says previous studies point to several reasons: “Oftentimes when people are experiencing stress in their life, having the social support of someone could help reduce that stress.”
It may also be the comfort of sharing expenses, such as housing, food, and insurance, reduces stress, she says.
“One partner might be more interested in healthy eating and that, sort of by osmosis, may influence the other partner in terms of their lifestyle choices as well,” Ford says.
Add Lower Blood Sugar to the Marriage Benefits
Other health benefits of living with a partner, particularly in older age, have been well-document in other studies. And studies have linked type 2 diabetes risk with lack of social support, loneliness, and isolation.
But those factors are complex and less easily tracked, so the team focused on easy-to-capture blood sugar levels.
They adjusted for factors that could affect results, such as whether the participants were retired or currently working and whether they reported depression or had changes in body mass index, as that number may change as vigorous exercise can become more difficult with age.
The authors note that this was an observational study of data so the study can't prove that marriage status causes differences in blood sugar levels.
However, a strength of the study is that it used HbA1c, which is a precise measure, as an outcome instead of a measure that relies on self-reported data.
A limitation is that the database, the English Longitudinal Study of Ageing, includes primarily white participants, so it's not clear whether the study's conclusions would hold true for other races, Ford says.
Using the Information
The data may have messages for middle-age and older adults and their doctors.
“If someone's going through a marital transition — whether they've lost a partner or are going through a divorce or separation -- for the clinician, it might be important to check these biomarkers, like HbA1c,” Ford says.
“Likewise, if older adults want to pursue romantic relationships and new partnerships, that should also be supported,” she says.