To assess efficacy and tolerability of insulin detemir or NPH insulin added to oral therapy for type 2 diabetes in a treat-to-target titration protocol. Individuals (n = 476) with HbA(1c) (A1C) 7.5-10.0% were randomized to addition of twice-daily insulin detemir or NPH insulin in a parallel-group, multicenter trial. Over 24 weeks, insulin doses were titrated toward prebreakfast and predinner plasma glucose targets of < or =6.0 mmol/l (< or =108 mg/dl). Outcomes assessed included A1C, percentage achieving A1C < or =7.0%, risk of hypoglycemia, and body weight. At 24 weeks, A1C had decreased by 1.8 and 1.9% (from 8.6 to 6.8 and from 8.5 to 6.6%) for detemir and NPH, respectively (NS). In both groups, 70% of participants achieved an A1C