Background: The benefits of sodium glucose cotransporters 2 (SGLT2) inhibitors in patients with type 2 diabetes mellitus include plasma glucose control, reduction in body weight and blood pressure, and low risk of hypoglycemia, although they may also cause genitourinary infections, polyuria, or volume depletion. It is not clear whether dapagliflozin, an SGLT2 inhibitor, improves treatment satisfaction among patients in a comprehensive way despite the negative side effects. This study assessed the effect of dapagliflozin on glycosylated hemoglobin (HbA1c), body weight, and treatment satisfaction in overweight patients with type 2 diabetes mellitus treated with oral hypoglycemic agents.Methods: This multicenter, open-label, single-arm observational study included patients with type 2 diabetes mellitus administering dapagliflozin 5 or 10 mg per day for 14 weeks. Changes in treatment satisfaction were evaluated using a new version of the Oral Hypoglycemic Agent-Questionnaire (OHA-Q ver. 2) consisting of 23 items. Correlation between treatment satisfaction and HbA1c levels and body weight were analyzed using the Spearman’s rank-correlation coefficient.Results: Of the 221 patients enrolled, 188 completed the study. Mean HbA1c decreased from 7.8 ± 0.7% (62.1 ± 7.5 mmol/mol) to 7.3 ± 0.8% (55.9 ± 8.7 mmol/mol) (change − 0.6 ± 0.7%,P < 0.001) and body weight decreased from 82.5 ± 14.6 to 80.7 ± 14.8 kg (change − 2.3 ± 2.8 kg,P < 0.001). OHA-Q ver. 2 was validated as well, the mean OHA-Q ver. 2 total score increased from 44.3 ± 9.4 to 46.6 ± 9.8 (best score 69, worst score 0; change 2.3 ± 6.6,P < 0.001). The change in body weight significantly correlated with the OHA-Q ver. 2 total score (Spearman’sρ = − 0.17,P = 0.035). The change in HbA1c levels significantly correlated with the satisfaction subscale score (Spearman’sρ = − 0.19,P = 0.011).Conclusions: Dapagliflozin significantly improved treatment satisfaction among patients with type 2 diabetes mellitus for 14 weeks. Body weight loss significantly correlated with treatment satisfaction.Trial registrationUMIN-CTR: UMIN000016304

Patient data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) are used to assess the effect of biguanide administration on rates of lactic acidosis (LA) in hospitalized diabetes mellitus (DM) patients. In this retrospective cohort study (from April 2013 to March 2016), we compare DM inpatients prescribed biguanides to DM inpatients who were not prescribed biguanides to quantify the association between biguanides and incidence of LA. In total, 8,111,848 DM patient records are retrieved from the NDB. Of the 528,768 inpatients prescribed biguanides, 782 develop LA. Of the 1,967,982 inpatients not prescribed biguanides, 1310 develop LA. The rate ratio of inpatients who develop LA and are administered biguanides to those who developed LA without receiving biguanides is 1.44 (95% CI, 1.32–1.58). Incidence rates and rate ratios for both sexes are elevated in the group prescribed biguanides for patients aged 70 years and older, markedly in those 80 years and older: 40.12 and 6.31 (95% CI, 4.75–8.39), respectively, for men and 34.96 and 5.40 (95% CI, 3.91–7.46), respectively, for women. Biguanides should be used conservatively in patients older than 70 years, particularly for those with comorbidities, and with caution in patients 80 years and older.