Novel subgroups of type 2 diabetes and their association with microvascular outcomes in an Asian Indian population: a data-driven cluster analysis: the INSPIRED study
Type 2 diabetes is known for considerable heterogeneity in its etiopathogenesis and clinical presentation. The identification of distinct clusters would help prevent the risk of diabetes-related complications. Ranjit and colleagues conducted a study titled “Novel subgroups of type 2 diabetes and their association with microvascular outcomes in an Asian Indian population: a data-driven cluster analysis: the INSPIRED study” published by the “British Medical Journal”. The summary of findings is below:
Objectives:
To identify type 2 diabetes clusters in Asian-Indians.
To investigate the clinical implications and outcomes of this clustering.
Method:
Across nine states of India, there was a selection of 19,084 individuals from a network of 50 diabetes centres. The participants (aged 10–97 years) had type 2 diabetes with diabetes duration of < 5 years at their first clinic visit. k-means clustering was performed by using different variables. It includes age at diagnosis, waist circumference, body mass index, glycated haemoglobin, serum high-density lipoprotein cholesterol, serum triglycerides, and C peptide (fasting and stimulated). The validation was conducted in a national epidemiological data set of representative individuals from 15 states across India.
Findings:
The investigation identified four clusters of patients differing in phenotypic characteristics along with disease outcomes. The four clusters are
1) Severe Insulin Deficient Diabetes (SIDD)
2) Insulin Resistant Obese Diabetes (IROD)
3) Combined Insulin Resistant and Deficient Diabetes (CIRDD)
4) Mild Age-Related Diabetes (MARD)
CIRDD accounts for a smaller number of patients with type 2 diabetes in the study population; however, this cluster represents a more aggressive phenotype. These individuals develop diabetes at a younger age and have poor metabolic control. Additionally, they have high serum triglyceride levels, a high risk of developing kidney disease, and retinopathy among all clusters. IROD individuals have better metabolic control than either SIDD or CIRDD, but also had a high risk of developing kidney disease. Individuals with SIDD phenotype had the worst metabolic control, slow progression to treatment goal, high risk of developing retinopathy.
The frequency of individuals with MARD phenotype was more. Although they have the onset of diabetes from lower age, they have the best metabolic control and the lowest risk of complications.
Limitations:
The authors acknowledge that institution was private and had a pay-for-service clinic. Hence, data on all variables in every patient is not available due to financial constraints. Additionally, this institution was a tertiary referral centre for diabetes. Hence, patients with more severe and advanced cases visit this clinic. This could have been an element of bias in these findings, the authors acknowledge.
Image Credit: Abstract photo created by freepic.diller – www.freepik.com
