Time to glucose peak shows utility as prediabetes risk stratification tool
Glucose peak >30 minutes appears to be a stronger independent indicator of prediabetes and β-cell function when compared with the monophasic glucose curve shape, according to a study, suggesting that time to glucose peak may be an important tool to enhance prediabetes risk stratification.
The cross-sectional study included 145 adults without diabetes (mean age 42 years; mean body mass index 29.2 kg/m2). Oral glucose tolerance test (OGTT) data were characterized by peak (30 vs >30 mins) and shape (biphasic vs monophasic). Prediabetes and disposition index (DI), a marker of β-cell function, were the main outcomes investigated.
The glucose curve shape of an OGTT was categorized as monophasic when plasma glucose increased to the maximum after 30 to 90 minutes and decreased until 120 minutes, with a final downward drop of at least 0.25 mmol/l between 90 and 120 minutes. On the other hand, glucose shapes that reached a nadir after an initial increase and increased again >0.25 mmol/l until 120 minutes were categorized as biphasic.
Results showed that of the participants, 36 percent had prediabetes. Glucose peak >30 minutes, but not monophasic curve, was associated with greater odds of prediabetes (odds ratio, 4.0 vs 1.1; p<0.001).
Both glucose peak >30 minutes and monophasic curve correlated with lower DI (p≤0.01). Time to glucose peak and glucose area under the curve independently predicted DI (p<0.001).
Prediabetes significantly increases the risk of developing diabetes. The condition may be effectively diagnosed using fasting and 2-hour glucose thresholds derived from the OGTT, although the predictive ability may differ by race or ethnicity and the incidence of diabetes in the population. [Diabetes Care 2017;40:S11-S24; JAMA 2015;314:1021-1029; Diabetes Care 2015;38:213-219]
According to researchers, assessing the morphological characteristics of the glucose curve (eg, time to glucose peak and curve shape) during an OGTT could be a useful indicator of prediabetes risk as the said characteristics may reflect different phenotypes of insulin secretion relative to insulin sensitivity.
The present finding that the time to glucose peak is a stronger independent indicator of prediabetes and β-cell function than glucose curve shape suggests that “the glucose peak parameter maximizes the information obtained from a single OGTT and could prove to be a valuable tool of high clinical and epidemiological significance because it can be simply derived and used in addition to glycaemic thresholds to enhance prediabetes risk stratification,” they added.