Association of Tourette Syndrome and Chronic Tic Disorder With Metabolic and Cardiovascular Disorders

IMPORTANCE: There are limited data concerning the risk of metabolic and cardiovascular disorders among individuals with Tourette syndrome (TS) or chronic tic disorder (CTD). OBJECTIVE: To investigate the risk of metabolic and cardiovascular disorders among individuals with TS or CTD over a period of 40 years. DESIGN, SETTINGS, AND PARTICIPANTS: This longitudinal population-based cohort study included all individuals living in Sweden between January 1, 1973, and December 31, 2013. Families with clusters of full siblings discordant for TS or CTD were further identified. Data analyses were conducted from August 1, 2017, to October 11, 2018. EXPOSURES: Previously validated International Classification of Diseases diagnoses of TS or CTD in the Swedish National Patient Register. MAIN OUTCOMES AND MEASURES: Registered diagnoses of obesity, dyslipidemia, hypertension, type 2 diabetes, and cardiovascular diseases (including ischemic heart diseases, arrhythmia, cerebrovascular diseases and transient ischemic attack, and arteriosclerosis). RESULTS: Of the 14 045 026 individuals in the cohort, 7804 individuals (5964 males [76.4%]; median age at first diagnosis, 13.3 years [interquartile range, 9.9-21.3 years]) had a registered diagnosis of TS or CTD in specialist care. Of 2 675 482 families with at least 2 singleton full siblings, 5141 families included siblings who were discordant for these disorders. Individuals with TS or CTD had a higher risk of any metabolic or cardiovascular disorders compared with the general population (hazard ratio adjusted by sex and birth year [aHR], 1.99; 95% CI, 1.90-2.09) and sibling controls (aHR for any disorder, 1.37; 95% CI, 1.24-1.51). Specifically, individuals with TS or CTD had higher risks for obesity (aHR, 2.76; 95% CI, 2.47-3.09), type 2 diabetes (aHR, 1.67; 95% CI, 1.42-1.96), and circulatory system diseases (aHR, 1.76; 95% CI, 1.67-1.86). The risk of any cardiometabolic disorder was significantly greater in males than in females (aHR, 2.13; 95% CI, 2.01-2.26 vs aHR, 1.79; 95% CI, 1.64-1.96), as was the risk of obesity (aHR, 3.24; 95% CI, 2.83-3.70 vs aHR, 1.97; 95% CI, 1.59-2.44). The risks were already evident from childhood (the groups were significantly different by age 8 years) and were significantly reduced with the exclusion of individuals with comorbid attention-deficit/hyperactivity disorder (aHR, 1.52; 95% CI, 1.42-1.62), while excluding other comorbidities did not significantly affect the results. Compared with pati