Elevated 1-hour post-load plasma glucose identifies obese youth with abnormal glucose metabolism and an unfavourable inflammatory profile.

CONTEXT

Adults with plasma glucose levels at one hour (1h-GL) ≥8.6 mmol/L during an oral glucose tolerance test (OGTT) are at increased risk for type 2 diabetes mellitus and present an unfavourable cardiometabolic and inflammatory profile, but relevant data on children are scarce.

OBJECTIVE

To investigate if elevated 1h-GL during OGTT in obese children and adolescents is associated with insulin resistance and specific pro-inflammatory biomarkers.

RESEARCH DESIGN AND METHODS

The study group comprised 88 obese children who attended the Outpatient Pediatric Clinic of our Hospital between January and December 2016. Children were divided into two groups according to 1h-GL during an OGTT: group 1 (n = 57) consisted of those with 1h-GL <8.6 mmol/L and group 2 (n = 31) of those with 1h-GL ≥8.6 mmol/L. Arterial blood pressure, body mass index (BMI) and waist circumference (WC) z-scores were measured in all participants. Specific insulin resistance (IR) indices, that is HOMA-IR, Matsuda index and Cederholm insulin sensitivity index (ISI) were calculated. Further, pro-inflammatory biomarkers that have been correlated with obesity complications, namely adiponectin, leptin, visfatin and interleukin (IL)-6 together with lipid levels were measured in all participants. Logistic regression analysis was used.

RESULTS

Children in group 2 had higher insulin (15.5 ± 6.4 vs 10.9 ± 4.8 μU/mL), HOMA-IR (3.41 ± 1.4 vs 2.34 ± 1.05) and lower Matsuda index [4.7 (3.1) vs 18.4 (17) median plus IQR] and Cederholm ISI (38 ± 6 vs 56 ± 11), than children in group 1 (all P < 0.001). They also had higher visfatin (15.4 ± 5.2 vs 10.1 ± 7 ng/mL), and IL-6 [12.5 (6.7) vs 4.8 (4.4) pg/mL], and lower adiponectin (5.9 ± 3.4 vs 11.8 ± 4.7 μg/mL) than children in group 1 (all P < 0.001). Logistic regression showed that these differences between the two groups were independent of age, sex, Tanner stage, BMI and WC z-scores.

CONCLUSIONS

In obese children, 1h-GL ≥8.6 mmol/L during an OGTT is correlated with worsened IR, and an unfavourable metabolic and inflammatory profile. Thus, 1h-GL could be used as an additional marker to identify obese children and adolescents at increased risk of developing obesity complications.