Gender-based differences in glycaemic control and hypoglycaemia prevalence in patients with type 2 diabetes: results from patient-level pooled data of six randomized controlled trials

Aims: To determine the impact of gender on glycaemic control and hypoglycaemia in insulin-naive patients with type 2 diabetes (T2DM). Methods: Data were pooled from six randomized clinical trials of insulin glargine or NPH insulin in insulin-naive, inadequately controlled patients. Female [n=1251; mean glycated haemoglobin (HbA1c) level 8.99%, age 56.91 years, diabetes duration 9.84 years] and male patients (n=1349; mean HbA1c 8.9%, age 57.47 years, diabetes duration 10.13 years) were started on and treated with insulin glargine or NPH insulin for 24-36 weeks. HbA1c and fasting blood glucose levels, percent achieving HbA1c target of <7% and insulin dose change were recorded. Results: For both men and women, HbA1c levels were significantly reduced over time (p<0.001); a significantly greater HbA1c reduction was observed inmen than in women (-1.36 vs. -1.22; p= 0.002). Significantly fewer women achieved target HbA1c of < 7% (p< 0.001). At the study end, women had a significantly higher insulin dose/kg than men (0.47 vs. 0.42 U/kg; p< 0.001). The incidence rates of severe and severe nocturnal hypoglycaemia were significantly higher in women (3.28% vs. 1.85%; p< 0.05 and 2.24% vs. 0.59%; p< 0.001, respectively). Women were more likely to experience severe hypoglycaemia [odds ratio (OR) 1.80; 95% confidence interval (CI) 1.08, 3.00; p= 0.02] and severe nocturnal hypoglycaemia (OR: 3.80; 95% CI 1.72, 8.42; p= 0.001). Conclusions: These observations confirm studies that found a smaller improvement in HbA1c and greater hypoglycaemia in women during insulin treatment. Physicians should be aware of the need to determine and closely monitor dosing, particularly in women, to optimize the balance between glycaemic control and hypoglycaemia risk.