Endocrinology · 1998
UK Prospective Diabetes Study (UKPDS 33)
In 1977, when Robert Turner and colleagues at Oxford began planning a long-term diabetes trial, type 2 diabetes management rested largely on clinical convention rather than outcome data. Diet control was the standard initial approach, and the question of whether driving blood glucose lower actually reduced complications, rather than merely improving a surrogate number, had never been settled in a properly controlled trial of meaningful size and duration.
The UKPDS recruited 5,102 patients with newly diagnosed type 2 diabetes at 23 centers across the United Kingdom and followed them for a median of ten years. Intensive glucose control using sulfonylureas or insulin brought median HbA1c to 7.0%, compared with 7.9% in the conventional diet-based group. The intensive group showed a 25% relative reduction in microvascular endpoints, including the need for retinal photocoagulation and the development of clinical proteinuria. A companion paper published simultaneously in the same Lancet issue showed that metformin, in overweight patients specifically, reduced diabetes-related death and myocardial infarction by margins that exceeded what glucose lowering alone could explain.
The metformin finding was particularly consequential because it separated glycemic effect from some broader metabolic or vascular benefit. Metformin moved to first-line status in overweight patients with type 2 diabetes as a direct result of that data, a position it holds in virtually every diabetes guideline published since. The macrovascular outcomes, however, did not improve as clearly as the microvascular ones under intensive glycemic control, and the trial forced a recognition that treating blood sugar addresses one dimension of cardiovascular risk without eliminating the need to manage blood pressure and lipids separately.
Rury Holman, who had collaborated with Turner throughout the trial, continued the follow-up program after Turner's death in 1999. The UKPDS post-trial cohort study, published in 2008, documented what the investigators called a legacy effect: patients who had been in the intensive control group during the trial continued to show reduced rates of microvascular and macrovascular complications a decade after the formal study ended, even though HbA1c values had converged between groups. This extended benefit from early, sustained glucose control became an important argument for treating aggressively at diagnosis rather than after complications appear.
The UKPDS defined HbA1c as the central treatment target for type 2 diabetes and produced a risk engine that clinicians still use to estimate complication probability. The trial's 23-center UK design and its ten-year follow-up gave it a scale and duration that smaller studies could not match, and its simultaneous publication of the metformin substudy in the same issue made 1998 the year that the modern framework for type 2 diabetes management arrived in print.
Key People
- Robert Turner — Lead UKPDS investigator at Oxford until his death in 1999
- Rury Holman — Co-investigator who led subsequent UKPDS analyses and the legacy study
- Irene Stratton — UKPDS biostatistician; co-author of the core microvascular outcomes paper
Lancet, 1998
Related landmarks
- 1994 · Discovery of Leptin (Endocrinology)
- 1993 · DCCT (Diabetes Control and Complications Trial) (Endocrinology)
- 2008 · ACCORD (Endocrinology)
- 1982 · Recombinant Human Insulin (Humulin) Approval (Endocrinology)