Researchers sought to identify the prevalence of metabolic syndrome in patients with type 1 diabetes and its relationship to diabetic complication development.
Metabolic syndrome is strongly associated with type 2 diabetes and insulin resistance. It encompasses certain cardiovascular risk factors, including abdominal obesity, dyslipidemia, hypertension, insulin resistance, and prothrombic and proinflammatory states. As obesity rates have risen, an association between metabolic syndrome and type 1 diabetes has developed. Prompt identification of these patients allows for rapid management and reduction of diabetic complications. Furthermore, previous studies have shown that metabolic syndrome in younger patients with type 2 diabetes reduces the complications as aging continues. The use of metformin in patients with type 1 diabetes has also been shown to reduce atherosclerotic events. Researchers in Australia examined metabolic syndrome prevalence in patients with type 1 diabetes and the relationship to microvascular and macrovascular complications across age groups. They also assessed the use of metformin in patients with type 1 diabetes.
Patients at least 18 years of age were included in the analysis. According to the World Health Organization criteria, metabolic syndrome was defined and required two of the following characteristics: hypertension, dyslipidemia, obesity, and microalbuminuria. Diabetes complications included retinopathy, end-stage renal disease, peripheral neuropathy, myocardial infarction, coronary artery bypass graft, stroke, peripheral vascular disease, foot ulcer, and lower limb amputation. 2,120 patients were identified from The Australian National Diabetes Information Audit and Benchmarking (ANDIAB), and statistical analysis was conducted utilizing chi-square tests and t-tests. At baseline, patients had an average diabetes duration of 18.5 years and an HbA1c of 8.2%.
The study’s results found that 30% of the patients had metabolic syndrome at baseline, with no statistically significant gender differences. As age increased, the prevalence of metabolic syndrome was higher with 21%, 35%, and 44% in the less than 40-year-old age group, 40–60-year-old age group, and more than 60-year age group (P<0.001), respectively. Hypertension was present in 89% of patients with metabolic syndrome, and either dyslipidemia, obesity, or microalbuminuria was present in 50% of the patients with metabolic syndrome. In contrast, there was a higher prevalence of dyslipidemia and microalbuminuria in patients less than 40 years old (P<0.05). Diabetes complications were also significantly higher in patients with metabolic syndrome. Retinopathy was present in 60% of patients with metabolic syndrome, compared to 31% in those without, and was the most prevalent complication.
Furthermore, the macrovascular disease was present in 38.8% of patients with metabolic syndrome compared to only 11.2% without metabolic syndrome (P<0.001). The odds ratio for each diabetic complication was significantly higher in the group with metabolic syndrome. Metabolic syndrome and prevalence of diabetic complications were most significant in the younger age group. The younger and middle age groups had a more significant association between metabolic syndrome and microvascular and foot complications. Similarly, the younger age group had the most important association between metabolic syndrome and macrovascular complications. Furthermore, metformin use did not benefit HbA1c in patients with metabolic syndrome and type 1 diabetes.
Metabolic syndrome in patients with type 1 diabetes was shown to significantly increase the risk of microvascular and macrovascular complications, including retinopathy, nephropathy, neuropathy, and macrovascular disease. The risk was higher in the younger age group with a sixfold, threefold, and fourfold increased odds of macrovascular, microvascular, and foot complications, respectively. A weakness of this study is the cross-sectional nature as patients were not followed to determine incidence. Insulin dose was also not measured to assess insulin resistance, a common characteristic of metabolic syndrome. In conclusion, metabolic syndrome was an essential indicator of diabetic complications in type 1 diabetes. The impact was highest in the younger age population, emphasizing a need for aggressive management.
- Patients with type 1 diabetes and metabolic syndrome have a two-to-three-fold increased risk of diabetic complications across all age groups.
- Metabolic syndrome is a helpful indicator to prevent and detect diabetic complications, especially in younger age groups.
- Future studies are needed to evaluate the impact of oral antihyperglycemic drugs on the burden of diabetic complications due to metabolic syndrome.
Lee AS, Twigg SM, Flack JR. Metabolic syndrome in type 1 diabetes and its association with diabetes complications. Diabet Med. 2021.
Grundy SM, Brewer HB, Cleeman JI, Smith SC, Lenfant C. Definition of Metabolic Syndrome: Report of the National Heart, Lung, and Blood Institute/American Heart Association Conference on Scientific Issues Related to Definition. Circulation; 2004.
Macrina Ghali, PharmD Candidate 2021, Florida A&M University, College of Pharmacy and Pharmaceutical Sciences