Comorbidity and glycemic control in patients with type 2 diabetes

Background: It is commonly believed that good glycemic control is hard to a chieve in patients with diabetes mellitus and concurrent chronic illnesses. Objective: To determine the impact of comorbidity on glycemic control at pr esentation and subsequent follow-up in patients with type 2 diabetes. Methods: We studied 654 consecutive patients who presented to a diabetes cl inic in 1997. Comorbidity was rated using the Chronic Disease Score (CDS) i ndex, which is a validated, weighted score that takes into account the pati ent's age, sex, and classes of medications. Univariate and multivariate lin ear regressions were used to determine the contribution of age, body mass i ndex (calculated as weight in kilograms divided by the square of height in meters), diabetes duration, type of therapy, and CDS to initial hemoglobin A(1c) (HbA(1c)) level. A similar analysis was performed for the 169 patient s with follow-up HbA(1c) levels 6 months after presentation. Results: Patients were 90% African American, and 66% female, with average a ge of 53 years. Average diabetes duration was 5 years; body mass index, 33; HbA(1c) level, 8.8%; and CDS, 1121 (range, 232-7953). At presentation, pat ients with higher CDSs tended to be older and to have a lower HbA(1c) level , but multivariate linear regression showed that receiving pharmacological therapy, younger age, and having a lower C-peptide level were the only sign ificant contributors to HbA(1c) level. In the 169 follow-up patients, prese nting characteristics were not significantly different from those of the fu ll cohort: average initial HbA(1c) level was 8.8%; CDS, 1073. Their HbA(1c) level at 6 months averaged 7.5% and the CDS had no significant impact on t heir follow-up HbA(1c) level. Conclusion: Comorbidity does not appear to limit achievement of good glycem ic control in patients with type 2 diabetes.