Evidence supporting an association between hypoglycemic events and depression

OBJECTIVES: This retrospective study investigated the association between hypoglycemic events (HEs) and depression events (DEs) in patients with diabetes mellitus (type 1 and type 2). METHODS: Analyzed data were from health care claims for individuals with employer-sponsored primary or Medicare supplemental insurance from the Thomson Reuters Market Scan database during the years 2008 and 2009. A baseline period (January 2008 to December 2008) was used to identify eligible patients and collect baseline clinical and demographic characteristics. Eligible patients were aged ≥18 years with diabetes (ICD-9-CM codes: 250.00, 250.01, 250.02, 250.03) who had not experienced any HEs or DEs and were not on antidepressant therapy during the baseline period. We studied the relationships between the DEs and HEs before and after adjusting for the covariates. RESULTS: Of the 923,024 patients meeting the inclusion criteria, 22,735 (2.46%) patients had HEs (ICD-9-CM coded: 251.0, 251.1, 251.2, 250.8) and 6164 (0.67%) patients had DEs (ICD-9-CM: 311) during the evaluation period. Patients reporting HEs had 78% higher odds of experiencing depression than patients without HEs before adjusting for the covariates. Similarly, after adjusting for the covariates, data indicated that patients with HEs had higher odds of experiencing depression (OR = 1.726; 95% CI = 1.52-1.96). Similar analyses in different age categories showed that the OR monotonically increases with age regardless of whether the other covariates are included in the model. CONCLUSIONS: ICD-9-CM-coded HEs were independently associated with an increased risk of DEs in patients with diabetes, and this incidence increased with the patients' age. KEY LIMITATIONS: A key limitation to this study is that only those HEs that resulted in health care provider contact and subsequent claims coding indicative of hypoglycemia were included. It is likely that many cases of mild hypoglycemia, particularly those not severe enough to warrant medical attention, were not captured in this study.