Achieving glycemic goal with initial versus sequential combination therapy using metformin and pioglitazone in type 2 diabetes mellitus

Methods for using clinical laboratory test results as baseline confounders in multi-site observational database studies when missing data are expected

PURPOSE

Our purpose was to quantify missing baseline laboratory results, assess predictors of missingness, and examine performance of missing data methods.

METHODS

Using the Mini-Sentinel Distributed Database from three sites, we selected three exposure-outcome scenarios with laboratory results as baseline confounders. We compared hazard ratios (HRs) or risk differences (RDs) and 95% confidence intervals (CIs) from models that omitted laboratory results, included only available results (complete cases), and included results after applying missing data methods (multiple imputation [MI] regression, MI predictive mean matching [PMM] indicator).

RESULTS

Scenario 1 considered glucose among second-generation antipsychotic users and diabetes. Across sites, glucose was available for 27.7-58.9%. Results differed between complete case and missing data models (e.g., olanzapine: HR 0.92 [CI 0.73, 1.12] vs 1.02 [0.90, 1.16]). Across-site models employing different MI approaches provided similar HR and CI; site-specific models provided differing estimates. Scenario 2 evaluated creatinine among individuals starting high versus low dose lisinopril and hyperkalemia. Creatinine availability: 44.5-79.0%. Results differed between complete case and missing data models (e.g., HR 0.84 [CI 0.77, 0.92] vs. 0.88 [0.83, 0.94]). HR and CI were identical across MI methods. Scenario 3 examined international normalized ratio (INR) among warfarin users starting interacting versus noninteracting antimicrobials and bleeding. INR availability: 20.0-92.9%. Results differed between ignoring INR versus including INR using missing data methods (e.g., RD 0.05 [CI -0.03, 0.13] vs 0.09 [0.00, 0.18]). Indicator and PMM methods gave similar estimates.

CONCLUSION

Multi-site studies must consider site variability in missing data. Different missing data methods performed similarly. Copyright © 2016 John Wiley & Sons, Ltd.

Association of self-monitoring of blood glucose use on glycated hemoglobin and weight in newly diagnosed, insulin-naïve adult patients with type 2 diabetes

BACKGROUND

Clinical trials have shown that self-monitoring of blood glucose (SMBG) combined with patient education and medication titration can lead to improved glycated hemoglobin (HbA1c) and reduced weight in recently diagnosed non-insulin-treated type 2 diabetes mellitus (T2DM) patients. This retrospective matched cohort study assessed the association of SMBG with achieving long-term clinical outcomes in these patients in a real-world clinical setting.

METHODS

Using electronic medical records (2008-2011), we selected a population of adult patients recently diagnosed with T2DM not receiving insulin who were SMBG users and a population of non-SMBG controls with similar demographic and clinical characteristics using propensity score matching. The main study outcomes compared between the two groups were time to achieve (1) HbA1c <7% for patients with baseline HbA1c ≥ 7% and (2) a ≥ 5% reduction in weight from baseline.

RESULTS

Of the 589 patients identified in each group, 113 in each group had a baseline HbA1c ≥ 7% (mean, 8.2%). The SMBG users were more likely to achieve an HbA1c <7% (12 months: 58.4% versus 38.9%, p = .0037; 36 months: 84.0% versus 70.0%, p = .0013) and to do so faster (median, 6.5 versus 20.5 months; log-rank p = .0016). Self-monitoring of blood glucose was associated with faster weight reduction (median time to achieve a ≥ 5% reduction, 23.5 versus 35.9 months for SMBG and non-SMBG, respectively; log-rank p = .0005).

CONCLUSIONS

In newly diagnosed T2DM insulin-naïve patients, SMBG users had an improved rate of achieving long-term glycemic control and weight loss in a real-world clinical setting.

Concomitant use of miglitol and mitiglinide as initial combination therapy in type 2 diabetes mellitus

AIM

To evaluate the efficacy of miglitol and mitiglinide alone or in combination on the metabolic profile and incretin secretion in Japanese type 2 diabetes patients.

METHODS

Patients on diet and exercise with or without metformin, were randomized to receive either miglitol, mitiglinide, or a combination, three times daily for 12 weeks.

RESULTS

At 12 weeks, HbA1c decreased significantly (p<0.001) and 1,5-AG increased significantly (p<0.001) in all three groups, with the greatest change seen with combination therapy. Effective improvement of postprandial hyperglycemia was demonstrated by a meal-loading test in all three interventions but serum insulin concentration was not increased by miglitol. In a subset of patients without prior metformin administration, faster and better glycemic control was achieved with the initial combination. After meal loading, serum total GLP-1 significantly increased only with miglitol monotherapy (p<0.05) and serum total GIP significantly decreased (p<0.01) in the arms employing miglitol after 12 weeks.

CONCLUSION

Miglitol/mitiglinide combination is more potent than monotherapy in improving glycemic control through the reduction of postprandial glucose excursion and the simultaneous sparing of additional insulin secretion. A marked difference in the effects of miglitol and mitiglinide on incretin secretion was also demonstrated.