Background: There is a resurgence of interest in the role of 1-hour post-load plasma glucose (PG) in risk stratification for type 2 diabetes and a cut-off of 8.6 mmol/L has been proposed to define dysglycaemia in addition to other existing criteria of prediabetes. We examined the efficacy of 1-hour PG level in predicting future type 2 diabetes in a longitudinal community-based cohort of Hong Kong Chinese.
Methods: Between 2001-2003, 489 adults without diabetes underwent 75-gram oral glucose tolerance test (OGTT). Blood samples were collected at 0, 15, 30, 60 and 120 minutes for measurement of plasma glucose and insulin levels. Between 2012-2014, progression to diabetes was ascertained either by reviewing medical records or by repeating OGTT and HbA1c. Area under the receiver-operating characteristic (ROC) curve was calculated to assess the discrimination of each parameter (fasting PG, 1-hour PG, 2-hour PG, disposition index) for development of diabetes. High 1-hour PG was defined using threshold of 8.6 mmol/L.
Results: Over 12-year follow-up, 46 people (9.4%) developed diabetes. The area under ROC curve were 0.79 (95% CI 0.71, 0.86) for fasting PG, 0.84 (95% CI 0.78, 0.89) for 1-hour PG, 0.79 (95% CI 0.72, 0.86) for 2-hour PG, and 0.78 (95% CI 0.71, 0.85) for disposition index with no difference between each parameter. In multivariate logistic regression, high 1-hour PG was associated with new-onset diabetes with odds ratio (OR) 4.87 (95% CI 1.91, 14.1, p=0.002), independent of impaired fasting glucose (OR 2.19 [95% CI 0.87, 5.32, p=NA), impaired glucose tolerance (OR 3.69 [95% CI 1.67, 8.27, p=0.001]) and other clinical variables including age, sex, smoking, family history of diabetes, history of gestational diabetes, waist and blood pressure.
Conclusions: One-hour PG is similar to fasting and 2-hour PG in prediction of type 2 diabetes. High 1-hour PG identifies people with high risk of diabetes independent of other criteria of prediabetes and clinical risk factors.
A. Luk: Research Support; Self; Bayer Healthcare Pharmaceuticals Inc., Roche Pharma. Other Relationship; Self; Merck Sharp & Dohme Corp. E.S. Lau: None. A.P. Kong: Advisory Panel; Self; Eli Lilly and Company. Research Support; Self; AstraZeneca. Speaker’s Bureau; Self; Abbott, AstraZeneca, Sanofi. Other Relationship; Self; AstraZeneca, Novartis Pharmaceuticals Corporation, Sanofi. E. Chow: None. R.C. Ma: Advisory Panel; Self; AstraZeneca. Stock/Shareholder; Self; GemVCare. Other Relationship; Self; AstraZeneca, Bayer Healthcare Pharmaceuticals Inc., Merck & Co., Inc., Novo Nordisk A/S, Pfizer Inc., Sanofi-Aventis, Tricida Inc. J.C. Chan: None.
