Post-Prandial Plasma Glucose Less Than or Equal to 70 mg/dL Is Not Uncommon in Young Japanese Women

Association of the extent of return to fasting state 2-hours after a glucose challenge with incident prediabetes and type 2 diabetes: The CARDIA study

AIM

To evaluate whether the extent of return to fasting state 2-hours after a glucose challenge among normoglycemic individuals is associated with lower risk of incident prediabetes/ type 2 diabetes in the Coronary Artery Risk Development in Young Adults (CARDIA) cohort study.

METHODS

We evaluated this association among 1879 normoglycemic adults who were categorized into three groups: 'Low post load' (2hPG < FPG); 'Medium post load' (2hPG ≥ FPG and < 75^th percentile of the difference); and 'High post load' (2hPG > FPG and ≥ 75^th percentile of the difference). We used Cox proportional hazards regression to evaluate the association of the difference in 2hPG and FPG with incident diabetes/prediabetes after adjustment for demographic and clinical covariates.

RESULTS

During 20 years of follow-up, 8% developed type 2 diabetes and 35% developed prediabetes. Compared to those with 'Low post load', the risk of type 2 diabetes was higher for participants with 'High post load' [HR: 1.56, 95% CI (1.03, 2.37)] and similar for participants with 'Medium post load' [HR: 0.99, 95% CI (0.64, 1.52)]. However, HRs for incident prediabetes among participants with 'High post load' [HR = 1.2, 95 %CI = (0.98, 1.46)] was not significantly different compared to participants with 'Low post load'.

CONCLUSION

Among normoglycemic individuals, a difference between 2hPG and FPG concentration > 0.9 mmol/L can be used to stratify individuals at higher risk for developing type 2 diabetes.

Decreased arterial distensibility and postmeal hyperinsulinemia in young Japanese women with family history of diabetes

INTRODUCTION

To assess vascular function and characterize insulin secretion using a physiological approach in Japanese women with family history of type 2 diabetes (FHD).

RESEARCH DESIGN AND METHODS

Standardized mixed-meal tests were performed with multiple postprandial glucose, insulin and free fatty acids (FFA) measurements over a 30-120 min period in 31 Japanese women aged 21-24 years. Arterial distensibility was assessed as well.

RESULTS

Fasting glucose, triglyceride and insulin averaged <90 mg/dL, <60 mg/dL and <5 μU/mL, respectively, and did not differ cross-sectionally between 10 with (FHD+) and 21 without FHD (FHD-). FHD+ showed higher insulin responses not only during the first 30 min (p=0.005) but also during the second hour (60-120 min, p<0,05) in spite of identical postprandial suppression of FFA and identical fasting and postprandial glucose and FFA concentrations, except for higher 60 min FFA in FHD+. Further, FHD+ had decreased arterial distensibility (p=0.003). On multivariate regression analysis, arterial distensibility emerged as the only significant independent predictor of FHD+. Endurance training in FHD+ did not alter decreased arterial distensibility whereas it abolished postprandial hyperinsulinemia.

CONCLUSIONS

FHD was associated with decreased arterial distensibility and postprandial hyperinsulinemia despite nearly identical postprandial glycemia and postprandial FFA suppression, suggesting that impaired vascular insulin sensitivity may precede glucose and lipid dysmetabolism in normal weight Japanese women aged 22 years.

Higher circulating adiponectin and lower orosomucoid were associated with postload glucose ≤70 mg/dL, a possible inverse marker for dysglycemia, in young Japanese women

OBJECTIVE

To examine whether serum adiponectin and orosomucoid were associated with postload glucose ≤70 mg/dL during an oral glucose tolerance test (OGTT), termed as postload low glycemia, a possible inverse marker for dysglycemia.

RESEARCH DESIGN AND METHODS

75 g OGTTs were performed with multiple postload glucose and insulin measurements over a 30-120 min period in 168 normal-weight Japanese women (18-24 years). Insulin resistance (IR) and β-cell function inferred from serum insulin kinetics during OGTT, fat mass and distribution by dual-energy X-ray absorptiometry (DXA), serum adiponectin and inflammatory markers were compared cross-sectionally between 39 women with and 129 women without postload low glycemia.

RESULTS

Of 168 women, 161 had normal glucose tolerance. Women with as compared with those without postload low glycemia had lower fasting and postload glycemia despite similar fasting and postload insulinemia. They had higher insulinogenic index (p=0.03) and lower adipose IR (a product of fasting free fatty acid and insulin, p=0.01), although DXA-derived general and central adiposity, the Matsuda Index and homeostasis model assessment-IR did not differ. In addition, they had higher adiponectin and lower orosomucoid (both p<0.001). Multivariate logistic regression analyses revealed that adiponectin (OR: 1.14, 95% CI 1.03 to 1.26, p=0.009) and orosomucoid (0.96, 0.93 to 0.97, p=0.008) were associated with postload low glycemia independently of adipose IR and insulinogenic index.

CONCLUSIONS

Higher adiponectin and lower orosomucoid were associated with 70 or lower mg/dL of postload glucose, a possible inverse marker for dysglycemia, in young women independently of DXA-derived fat mass and distribution, insulin secretion and IR.

Higher Fasting and Postprandial Free Fatty Acid Levels Are Associated With Higher Muscle Insulin Resistance and Lower Insulin Secretion in Young Non-Obese Women

Background

To assess the relationship of the shape of glucose concentration curve during a standardized meal test to serum free fatty acid (FFA) concentrations, insulin resistance and insulin secretion in young non-obese women.

Methods

Thirty-five young women had a standardized meal for breakfast with measurement of glucose, insulin and FFA concentrations at 0 (fasting), 30, 60 and 120 min; the areas under the concentration curves were calculated (AUCg, AUCi and AUCffa, respectively). Meal-induced insulin response (MIR) was calculated as the ratio between the incremental insulin and glucose concentrations during the first 30 min of meal tests. In two women (group A), post-breakfast glucose (PBG) returned to levels below fasting plasma glucose (FPG) at 30 min; in 15 and 11 women, PBG returned to levels below FPG at 60 and 120 min (groups B and C, respectively). In the remaining seven women (group D), PBG never fell below FPG.

Results

Despite no difference in fasting insulin and AUCi, fasting FFA, AUCg and AUCffa were the lowest in group A, increased linearly from group B to C and plateaued in group D, whereas MIR might be the highest in group A, decreased from group B to C and plateaued in group D.

Conclusion

Young women whose PBG returned to FPG more slowly had higher muscle insulin resistance and lower MIR associated with higher fasting and postprandial FFA levels compared with young women whose PBG returned to baseline more quickly.