Association between Metabolic Syndrome and Microvascular Complications in Chinese Adults with Type 1 Diabetes Mellitus (Diabetes Metab J 2022;46:93-103)

Corresponding author: Gyuri Kim https://orcid.org/0000-0002-2242-2816 Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 06351, Korea E-mail: gyuri5.kim@samsung.com Metabolic syndrome is a cluster of metabolic abnormalities including central obesity, impaired glucose tolerance, dyslipidemia, and hypertension [1]. Numerous previous studies have highlighted its importance due to the associated risk with type 2 diabetes mellitus, cardiovascular disease, and mortality, in relation to insulin resistance. The prevalence and incidence of metabolic syndrome have increased worldwide and it may have a significant impact on public health. Although several studies revealed that metabolic syndrome in patients with type 1 diabetes mellitus (T1DM) is also common and increased in Western populations, the prevalence of metabolic syndrome and its relationship with diabetes-related complications in patients with T1DM in Asian countries are not well established. In this article, entitled “Association between metabolic syndrome and microvascular complications in Chinese adults with type 1 diabetes mellitus,” Huang et al. [2] explored the prevalence of metabolic syndrome among adult patients with T1DM in China and evaluated its association with risk factors and microvascular complications. The prevalence of metabolic syndrome in the study population was 15.1%. Huang et al. [2] showed that female sex (odds ratio [OR], 2.86; 95% confidence interval [CI], 1.63 to 5.02; P=0.047), longer diabetes duration (OR, 1.04; 95% CI, 1.00 to 1.08; P<0.001), higher body mass index (OR, 1.14; 95% CI, 1.03 to 1.25; P=0.009), glycosylated hemoglobin (HbA1c) (OR, 1.23; 95% CI, 1.11 to 1.36; P< 0.001), and nutrition therapy (OR, 0.46; 95% CI, 0.26 to 0.78; P=0.005) were significantly associated with the prevalence of metabolic syndrome in patients with T1DM. After adjusting for sex, age, diabetes duration, HbA1c, and other lifestyle and socioeconomic factors, metabolic syndrome was independently associated with the presence of diabetic kidney disease (DKD) (OR, 2.14; 95% CI, 1.12 to 4.11; P=0.022) and diabetic retinopathy (DR) (OR, 3.72; 95% CI, 1.59 to 8.72; P=0.002). These findings are consistent with previous reports that have shown an association between metabolic syndrome and albuminuria, DKD, and DR in patients with T1DM [3]. However, there are several issues to be discussed. First, as noted by the authors, insulin dose and medications for hypertension and dyslipidemia are important variables to define and characterize patients with metabolic syndrome and T1DM, but these data were missing from the study. Intensive insulin therapy at high dosages can cause weight gain and increased insulin dose can be a clinical indicator of insulin resistance [4]. There was a relationship between intensive insulin treatment and a higher subsequent prevalence of metabolic syndrome [5]. In addition, the presence of insulin resistance in patients with T1DM may lead to quantitative lipid abnormalities. However, although most patients with T1DM showed abLetter