The following is a summary of “Recent Secular Trends of Body Mass Index in Individuals With Bipolar Disorders and in the General Population,” published in the September 2023 issue of Psychiatry by Najar et al.
Researchers performed a retrospective study to investigate secular trends and distribution of body mass index (BMI) in bipolar disorder and the general population from 2008 to 2019.
They obtained data from the National Quality Register for Bipolar Disorder, with bipolar disorders, and the National Living Conditions Survey. Quantile regression was used to compare the 15th, 50th, and 85th percentiles of BMI across age and study years.
The results showed 22,127 individuals with bipolar disorders (mean age: 48 years; 63% women) and 71,894 individuals from the general population (mean age: 52 years; 51% women). Among individuals with bipolar disorders, BMI percentiles were higher. At the 50th percentile, the BMI group differences were 1.1 (95% CI=0.8–1.14) for men and 1.8 (95% CI=1.5–2.1) for women. The widest gap was observed at the 85th BMI percentile: 2.3 (95% CI=1.8–2.8) for men and 4.1 (95% CI=3.7–4.6) for women. BMI increased over time in both study groups but more in the bipolar disorders group. The changes per decade in mean BMI were 0.4 (95% CI=0.3–0.5) for men in the general population, 1.1 (95% CI=0.7–1.4) for men with bipolar disorders, 0.6 (95% CI=0.5–0.7) for women in the general population, and 1.4 (95% CI=1.1–1.7) for women with bipolar disorders. Women with bipolar disorders had the highest prevalence and the greatest rate of increase in obesity. Obesity rates were higher in individuals with bipolar disorders (2019), 33% among women and 29% among men, compared to 13% and 15% in the general population.
They concluded that adults with bipolar disorder have a greater risk of obesity and cardiometabolic disease.