Elevated prevalence rates of metabolic syndrome and insulin resistance were observed in patients with newly diagnosed bipolar disorder, according to cross-sectional study results published in the International Journal of Bipolar Disorders.
Investigators conducted a cross-sectional study of baseline data from the longitudinal Bipolar Illness Onset Study, which recruited patients with bipolar disorder from the greater Copenhagen area in Denmark. With patient consent, unaffected first-degree relatives of patients were also invited to participate in the study. Age- and sex-matched healthy individuals were recruited from a blood donor center in Copenhagen. Participants underwent a series of clinical and laboratory tests; patients with bipolar disorder were also assessed for psychiatric symptom severity and medication use. Metabolic syndrome was defined according to the International Diabetes Federation 2006 criteria and constitutes a group of cardiovascular disease risk factors including abdominal obesity, diabetes and/or raised fasting glucose, dyslipidemia, and high blood pressure; insulin resistance was calculated from fasting plasma glucose and insulin levels per the homeostasis model assessment of insulin resistance. Prevalence rates of metabolic syndrome and insulin resistance were compared in all 3 study groups.
The final study cohort comprised 206 individuals with newly diagnosed bipolar disorder, 50 of their relatives, and 109 controls. The majority of patients (94.7%) with bipolar disorder had received their diagnosis within the prior 2 years. Metabolic syndrome was present in 15.0% of patients, 6.0% of their unaffected relatives, and 5.5% of healthy controls. After adjusting for age and sex, patients with bipolar disorder had a 3.5-fold greater risk for metabolic syndrome compared with healthy controls (odds ratio [OR], 3.529; 95% CI, 1.378-9.041; P =.009). No significant difference was observed between unaffected relatives and healthy controls (P =.6). The median (interquartile range) homeostasis model assessment of insulin resistance value was 2.06 (1.44 to 3.25) in patients, 2.10 (1.59 to 2.63) in unaffected relatives, and 1.73 (1.35 to 2.42) in healthy individuals. In the age- and sex-adjusted model, levels of insulin resistance were greater in patients compared with healthy controls (OR, 1.203; 95% CI, 1.059-1.367; P =.005), although not compared with relatives (P =.1). Of note, in the fully adjusted model controlling for smoking status and alcohol use, the observed differences between patients and healthy controls were no longer significant.
These data identify an elevated risk for metabolic syndrome and insulin resistance in patients with newly diagnosed bipolar disorder. Thus, screening for these conditions in patients may be important in reducing the risk for cardiovascular disease and premature death. As elevated risk in patients was strongly driven by smoking, cessation efforts may also be important for curbing the risk for metabolic syndrome and insulin resistance.
Coello K, Vinberg M, Knop FK, et al. Metabolic profile in patients with newly diagnosed bipolar disorder and their unaffected first‑degree relatives [published online April 2, 2019]. Int J Bipolar Disord. doi:10.1186/s40345-019-0142-3