Family history of type 2 diabetes may signify increased complication risk in type 1 diabetes
medwireNews: Having first-degree relatives with type 2 diabetes may be associated with an increased risk for cardiovascular disease and microvascular complications among people with type 1 diabetes, particularly those diagnosed at a young age, study findings suggest.
The researchers used the Taiwan National Health Insurance Research Database to evaluate complication rates in 11,237 individuals with type 1 diabetes who were enrolled in the program between 1995 and 2017.
As reported in JAMA Network Open, the 1302 people who had a first-degree relative with type 2 diabetes had a significantly higher risk for nephropathy, retinopathy, peripheral neuropathy, and hyperlipidemia than the 9935 who did not, with hazard ratios (HRs) ranging from 1.24 to 1.44 after adjustment for a range of comorbidities.
Rates of nephropathy were 21.20% for people with a family history of diabetes compared with 18.53% for those without, and the corresponding rates of retinopathy, peripheral neuropathy, and hyperlipidemia were 18.59% versus 16.52%, 12.83% versus 11.37%, and 27.88% versus 26.69%. The average time from type 1 diabetes diagnosis to the development of complications was 8.59 years.
Sheng-Hwu Hsieh (Chang Gung Memorial Hospital, Taoyuan City, Taiwan) and colleagues found that rates of major adverse cardiovascular events (MACE) were numerically higher among people with versus without a family history of diabetes (3.15 vs 2.94%), but the adjusted HR did not reach statistical significance.
However, when people with type 1 diabetes were categorized by age at diagnosis, having a family history of type 2 diabetes was significantly associated with increased MACE risk among the 5691 diagnosed before 20 years, at rates of 2.72% versus 0.59% among those without type 2 diabetes in their immediate family (adjusted HR=2.61). There was no significant association between these variables in people diagnosed with type 1 diabetes at an older age.
Similarly, rates of hypertension and hyperlipidemia were significantly higher in people with versus without a family history of type 2 diabetes for those younger than 20 years at diagnosis, but not for older people, supporting “the concept that insulin resistance is associated with the development of MACEs in patients with [type 1 diabetes] diagnosed early in life,” write Hsieh et al.
Taken together, the study results “suggest that a family history of [type 2 diabetes] may be a useful marker to identify a subgroup of patients with [type 1 diabetes] with an increased risk of developing MACEs,” they say.
The authors caution that family history of type 2 diabetes is a proxy measure of insulin resistance that “does not account for the associations between the genetic and environmental factors of insulin resistance,” and that their study could not demonstrate a causal association between the variables evaluated.
Therefore, “[f]urther investigations, including prospective analyses, are needed to clarify the association between insulin resistance and MACEs in [type 1 diabetes],” they conclude.
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2021 Springer Healthcare Ltd, part of the Springer Nature Group