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.

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at