Can long-term use of beta blockers or selective serotonin reuptake inhibitors (SSRIs) be implicated in the development of type 2 diabetes?—JUDITH LARA, PA, Berkeley, Calif.

Beta blockers and thiazide diuretics were implicated as independent factors for increasing the risk of diabetes in a prospective study of three separate cohorts. Age-adjusted relative risk was 1.37 (confidence interval [CI] 1.12-1.67) for thiazides and 1.26 (CI 1.06-1.50) for beta blockers (Diabetes Care. 2006;29:1065-1070). In a large-sample (2,391 subjects) nested cohort study with follow-up of four years or more, concomitant use of SSRIs and tricyclic antidepressants was shown to be associated with an increased risk of diabetes (odds ratio 1.89, CI 1.35-2.65), but neither was significant alone. Depression has long been associated with an increased risk of diabetes, so it is unknown whether the treatment or the diagnosis is more causal (Diabetes Res Clin Pract. 2008;79:61-67). Another prospective study comparing two antihypertensive regimens (beta blocker and thiazide or calcium channel blocker and ACE inhibitor) showed a significantly higher incidence of new-onset diabetes in those on the beta blocker and thiazide combination (Diabetes Care. 2008;31:982-988). This should prompt clinicians to encourage weight loss, proper diet, and exercise along with regular monitoring for diabetes risk in patients taking these drugs.—Claire Babcock O’Connell, MPH, PA-C (134-2)