Prevalence of Insomnia in Type 2 Diabetes Mellitus Patients at a Tertiary Care Centre in Southern Kerala

OBJECTIVE: This study aimed to assess the prevalence, patterns, and associated factors of insomnia among patients with type 2 diabetes mellitus (T2DM) and to identify comorbid conditions that may contribute to sleep disturbances in this population. METHODOLOGY: This cross-sectional study was conducted from 2022 to 2025 at a tertiary healthcare facility in Thiruvalla, Kerala, India. Using convenience sampling, 250 patients with T2DM were recruited. Patient demographic data, clinical history, and comorbidities were collected using a structured form. Insomnia was assessed using the Indian Insomnia Rating Scale (IIRS), a validated Malayalam-translated questionnaire. The IIRS scores were categorized as follows: 0-4, no insomnia; 5-10, mild insomnia; 11-20, moderate insomnia; and 21-30, severe insomnia. The T2DM was diagnosed according to the American Diabetes Association (ADA) criteria. Data analysis was performed using SPSS Statistics version 25 (IBM Corp., Armonk, NY, USA) to identify factors associated with insomnia in this population. RESULTS: Among the 250 participants, 141 (56.4%) were female, and 109 (43.6%) were male. Insomnia was reported in 101 (40.4%) participants, of whom 84 (83.2%) had secondary insomnia and 17 (16.8%) had primary insomnia. Difficulty falling asleep was reported by 48 (47.5%) participants, early awakening by 30 (29.7%), and difficulty maintaining sleep by 25 (24.8%). Duration of diabetes (p = 0.006), postprandial blood sugar (p = 0.002), and HbA1c (p = 0.002) were significantly associated with insomnia, whereas age, sex, occupation, and fasting blood glucose were not. The observed associations with glycemic parameters demonstrated small effect sizes. CONCLUSION: Insomnia is common among patients with T2DM. The findings demonstrate an association between poor glycemic control and insomnia; however, causality cannot be established due to the cross-sectional study design. Healthcare providers should implement routine screening for insomnia, optimize glycemic control, address comorbid conditions such as obstructive sleep apnea and peripheral neuropathy, and provide sleep hygiene counseling as part of comprehensive diabetes management programs.