Impaired Glucose-Stimulated Proinsulin Secretion Is an Early Marker of β-Cell Impairment Before Prediabetes Stage

2019 ◽  
Vol 104 (10) ◽  
pp. 4341-4346 ◽  
Author(s):  
Ying Yang ◽  
Min Wang ◽  
Jingzhi Tong ◽  
Zuoliang Dong ◽  
Min Deng ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Plasma Glucose ◽  
Cell Function ◽  
Normal Glucose Tolerance ◽  
Β Cell ◽  
Family History Of Diabetes ◽  
Postprandial Plasma Glucose ◽  
Patients With Diabetes ◽  
Β Cell Function ◽  
Early Biomarker

Abstract Context Evidence indicates that there is substantial impairment/loss of β-cell function/mass even before prediabetes. Elevated plasma proinsulin is a sign of β-cell dysfunction in patients with diabetes/prediabetes. However, the dynamic changes of glucose stimulated proinsulin secretion (GSPS) among nondiabetic individuals remain obscure. Objective To examine GSPS and glucose-stimulated insulin secretion (GSIS) among individuals with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) and to evaluate whether impaired GSPS is an early biomarker of β-cell impairment in individuals with NGT who have subthreshold postprandial plasma glucose (PPG). Design and Participants We evaluated GSPS and GSIS in 116 Chinese adults without diabetes (mean age ± SD, 33.31 ± 9.10 years; mean BMI, 25.24 ± 4.20 kg/m2) with fasting plasma glucose (FPG) < 5.6 mmol/L. Based on 2hPPG, the participants were divided into three groups: NGT1 (2hPPG < 6.67 mmol/L), NGT2 (6.67 ≤ 2hPPG < 7.78 mmol/L), and IGT (7.78 ≤ 2hPPG<11.1 mmol/L). We analyzed the association of GSIS and GSPS with commonly used indexes of β-cell function, insulin resistance and family history of diabetes. Results Although not diagnosed with prediabetes, the individuals with NGT2 have clinical characteristics and high diabetes risk factors similar to those of the IGT group. However, unlike individuals with IGT, NGT2 participants did not exhibit a delayed GSIS. Instead, GSPS was impaired in NGT2 groups but not in NGT1 group. Conclusions This study suggests that impaired GSPS, but not impaired GSIS, may serve as an early biomarker to identify a subpopulation of NGT with a high risk of diabetes.

scholarly journals The effect of vitamin D supplementation on the glycemic control of pre-diabetic Qatari patients in a randomized control trial

BMC Nutrition ◽  
2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohammed Al Thani ◽  
Eman Sadoun ◽  
Angeliki Sofroniou ◽  
Amin Jayyousi ◽  
Khaled Ahmed Mohamed Baagar ◽  
...  
Keyword(s):  
Vitamin D ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Plasma Glucose ◽  
Cell Function ◽  
Vitamin D Supplementation ◽  
Β Cell ◽  
Baseline Serum ◽  
Link Type ◽  
Β Cell Function

Abstract Background Vitamin D deficiency is associated with indicators of pre-diabetes including, insulin resistance, β-cell dysfunction and elevated plasma glucose with controversial findings from current trials. This study aims to investigate the long-term effect of vitamin D on glucose metabolism and insulin sensitivity in pre-diabetic and highly vitamin-deficient subjects. Methods One hundred thirty-two participants were randomized to 30,000 IU vitamin D weekly for 6 months. Participants underwent oral glucose tolerance test (OGTT) at 3-month intervals to determine the change in plasma glucose concentration at 2 h after 75 g OGTT (2hPCG). Secondary measurements included glycated hemoglobin, fasting plasma glucose and insulin, post-prandial insulin, indices of insulin sensitivity (HOMA-IR, Matsuda Index), β-cell function (HOMA-β, glucose and insulin area under the curve (AUC), disposition and insulinogenic indices), and lipid profile. Results A total of 57 (vitamin D) and 75 (placebo) subjects completed the study. Mean baseline serum 25(OH) D levels were 17.0 ng/ml and 14.9 ng/ml for placebo and vitamin D group, respectively. No significant differences were observed for 2hPC glucose or insulin sensitivity indices between groups. HOMA-β significantly decreased in the vitamin D group, while area under curve for glucose and insulin showed a significant reduction in β-cell function in both groups. Additionally, HOMA-β was found to be significantly different between control and treatment group and significance persisted after adjusting for confounding factors. Conclusion Vitamin D supplementation in a pre-diabetic and severely vitamin-deficient population had no effect on glucose tolerance or insulin sensitivity. The observed reduction in β-cell function in both placebo and vitamin D groups could be attributed to factors other than supplementation. Trial registration NCT02098980, 28/03/2014 (www.clinicaltrials.gov).

scholarly journals The effect of vitamin D supplementation on the glycemic control of pre-diabetic Qatari patients in a randomized control trial.

2019 ◽  
Author(s):  
Mohammed Al Thani ◽  
Eman Sadoun ◽  
Angeliki Sofroniou ◽  
Amin Jayyousi ◽  
Khaled Ahmed Mohamed Baagar ◽  
...  
Keyword(s):  
Vitamin D ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Plasma Glucose ◽  
Cell Function ◽  
Vitamin D Supplementation ◽  
Oral Glucose ◽  
Β Cell ◽  
Baseline Serum ◽  
Β Cell Function

Abstract Background: Vitamin D deficiency is associated with indicators of pre-diabetes including, insulin resistance, β-cell dysfunction and elevated plasma glucose with controversial findings from current trials. This study aims to investigate the long-term effect of vitamin D on glucose metabolism and insulin sensitivity in pre-diabetic and highly vitamin-deficient subjects. Methods: 132 participants were randomized to 30,000 IU vitamin D weekly for 6 months. Participants underwent oral glucose tolerance test (OGTT) at 3-month intervals to determine the change in plasma glucose concentration at 2h after 75g OGTT (2hPCG). Secondary measurements included glycated hemoglobin, fasting plasma glucose and insulin, post-prandial insulin, indices of insulin sensitivity (HOMA-IR, Matsuda Index), β-cell function (HOMA-β, glucose and insulin area under the curve (AUC), disposition and insulinogenic indices), and lipid profile. Results: A total of 57 (vitamin D) and 75 (placebo) subjects completed the study. Mean baseline serum 25(OH) D levels were 17.0 ng/ml and 14.9 ng/ml for placebo and vitamin D group, respectively. No significant differences were observed for 2hPC glucose or insulin sensitivity indices between groups. HOMA-β significantly decreased in the vitamin D group, while area under curve for glucose and insulin showed a significant reduction in β-cell function in both groups. Additionally, HOMA-β was found to be significantly different between control and treatment group and significance persisted after adjusting for confounding factors. Conclusion: Vitamin D supplementation in a pre-diabetic and severely vitamin-deficient population had no effect on glucose tolerance or insulin sensitivity. The observed reduction in β-cell function in both placebo and vitamin D groups could be attributed to factors other than supplementation. Trial registration: The trial was registered at www.clinicaltrials.gov with number: NCT02098980.

scholarly journals The Normal Glucose Tolerance Continuum in Obese Youth: Evidence for Impairment in β-Cell Function Independent of Insulin Resistance

2005 ◽  
Vol 90 (2) ◽  
pp. 747-754 ◽  
Author(s):  
Catherine W. Yeckel ◽  
Sara E. Taksali ◽  
James Dziura ◽  
Ram Weiss ◽  
Tania S. Burgert ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Glucose Tolerance ◽  
Cell Function ◽  
Normal Glucose Tolerance ◽  
Β Cell ◽  
Obese Youth ◽  
Normal Glucose ◽  
Β Cell Function

scholarly journals The effect of vitamin D supplementation on the glycemic control of pre-diabetic Qatari patients in a randomized control trial.

2019 ◽  
Author(s):  
Mohammed Al Thani ◽  
Eman Sadoun ◽  
Angeliki Sofroniou ◽  
Amin Jayyousi ◽  
Khaled Ahmed Mohamed Baagar ◽  
...  
Keyword(s):  
Vitamin D ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Plasma Glucose ◽  
Cell Function ◽  
Vitamin D Supplementation ◽  
Oral Glucose ◽  
Β Cell ◽  
Baseline Serum ◽  
Β Cell Function

Abstract Background: Vitamin D deficiency is associated with indicators of pre-diabetes including, insulin resistance, β-cell dysfunction and elevated plasma glucose with controversial findings from current trials. This study aims to investigate the long-term effect of vitamin D on glucose metabolism and insulin sensitivity in pre-diabetic and highly vitamin-deficient subjects. Methods: 132 participants were randomized to 30,000 IU vitamin D weekly for 6 months. Participants underwent oral glucose tolerance test (OGTT) at 3-month intervals to determine the change in plasma glucose concentration at 2h after 75g OGTT (2hPCG). Secondary measurements included glycated hemoglobin, fasting plasma glucose and insulin, post-prandial insulin, indices of insulin sensitivity (HOMA-IR, Matsuda Index), β-cell function (HOMA-β, glucose and insulin area under the curve (AUC), disposition and insulinogenic indices), and lipid profile. Results: A total of 57 (vitamin D) and 75 (placebo) subjects completed the study. Mean baseline serum 25(OH) D levels were 17.0 ng/ml and 14.9 ng/ml for placebo and vitamin D group, respectively. No significant differences were observed for 2hPC glucose or insulin sensitivity indices between groups. HOMA-β significantly decreased in the vitamin D group, while area under curve for glucose and insulin showed a significant reduction in β-cell function in both groups. Additionally, HOMA-β was found to be significantly different between control and treatment group and significance persisted after adjusting for confounding factors. Conclusion: Vitamin D supplementation in a pre-diabetic and severely vitamin-deficient population had no effect on glucose tolerance or insulin sensitivity. The observed reduction in β-cell function in both placebo and vitamin D groups could be attributed to factors other than supplementation. Trial registration: NCT02098980, 28/03/2014 (www.clinicaltrials.gov).

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