OGTT reveals high rate of diabetes in hypertensive patients - Beijing study

by Michael Woodhead

There is a high prevalence of diabetes and newly-detected diabetes among Chinese hypertensive outpatients, Beijing researchers have shown.

About one in four hypertensive outpatients had concomitant diabetes, and approximately one in three cases were newly detected , their study found.

Dr Wang Wei and co-researchers at the Beijing An Zhen Hospital, Capital Medical University and the Beijing Institute of Heart, Lung and Blood Vessel Diseases say that additional testing of 2-hour plasma glucose with an oral glucose tolerance test (OGTT) should be added to fasting plasma glucose (FPG) assay to improve the detection rate of diabetes, especially in elderly patients.

In a study of 4942 patients attending hypertension outpatient clinics in 46 hospitals in 22 provinces of China, the researchers measured fasting plasma glucose in all patients and also did 2-hour plasma glucose testing in those without a history of diabetes.

The study found that the prevalence of diabetes was 24% (both previously and newly diagnosed cases). Among the 1202 patients with diabetes, one third were newly detected. In patients aged <45 years, 53% of cases of diabetes were newly detected. Of the 417 cases of newly detected diabetes, 55% were identified using FPG tests and the remaining 45% by 2-hPG tests. More than a quarter of patients with newly detected diabetes had FPG <6.1 mmol/L and 16.5% had FPG <5.6 mmol/L. Among the elderly patients, 32.4% had normal FPG (<6.1 mmol/L) and 24.5% had optimal FPG (<5.6 mmol/L).

The detection rate of newly diagnosed diabetes was higher in patients with low educational level, low level of medical insurance, obesity and high triglycerides.

The researchers say that currently only the fasting plasma glucose assay is routinely used in China because of its technical convenience and low cost. However, they say their findings show that adding 2-hour plasma glucose to the routine FPG assay would increase detection rates by 4.5%, and by more than 6% in the elderly.

Source: BMJ Open