scholarly journals Insulin resistance in an animal model of polycystic ovary disease is aggravated by vitamin D deficiency: Vascular consequences

2018 ◽  
Vol 15 (4) ◽  
pp. 294-301 ◽  
Author(s):  
Leila Hadjadj ◽  
Szabolcs Várbíró ◽  
Eszter Mária Horváth ◽  
Anna Monori-Kiss ◽  
Éva Pál ◽  
...  

Hyperandrogenic state in females is accompanied with metabolic syndrome, insulin resistance and vascular pathologies. A total of 67%–85% of hyperandrogenic women suffer also from vitamin D deficiency. We aimed to check a potential interplay between hyperandrogenism and vitamin D deficiency in producing insulin resistance and effects on coronary resistance arteries. Adolescent female rats were divided into four groups, 11–12 animals in each. Transdermal testosterone-treated and vehicle-treated animals were kept either on vitamin D-deficient or on vitamin D-supplemented diet for 8 weeks. Plasma sexual steroid, insulin, leptin and vitamin D plasma levels were measured, and oral glucose tolerance test was performed. In coronary arterioles, insulin receptor and vitamin D receptor expressions were tested by immunohistochemistry, and insulin-induced relaxation was measured in vitro on isolated coronary resistance artery segments. Testosterone impaired glucose tolerance, and it diminished insulin relaxation but did not affect the expression of insulin and vitamin D receptors in vascular tissue. Vitamin D deficiency elevated postprandial insulin levels and homeostatic model assessment insulin resistance. It also diminished insulin-induced coronary arteriole relaxation, while it raised the expression of vitamin D and insulin receptors in the endothelial and medial layers. Our conclusion is that both hyperandrogenism and vitamin D deficiency reduce sensitivity of coronary vascular tissue to insulin, but they do it with different mechanisms.

2019 ◽  
Vol 35 (6) ◽  
pp. 535-538 ◽  
Author(s):  
Erdem Sahin ◽  
Ilknur Col Madendag ◽  
Mefkure Eraslan Sahin ◽  
Yusuf Madendag ◽  
Gokhan Acmaz ◽  
...  

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1751
Author(s):  
Saroj Khatiwada ◽  
Virginie Lecomte ◽  
Michael F. Fenech ◽  
Margaret J. Morris ◽  
Christopher A. Maloney

Obesity increases the risk of metabolic disorders, partly through increased oxidative stress. Here, we examined the effects of a dietary micronutrient supplement (consisting of folate, vitamin B6, choline, betaine, and zinc) with antioxidant and methyl donor activities. Male Sprague Dawley rats (3 weeks old, 17/group) were weaned onto control (C) or high-fat diet (HFD) or same diets with added micronutrient supplement (CS; HS). At 14.5 weeks of age, body composition was measured by magnetic resonance imaging. At 21 weeks of age, respiratory quotient and energy expenditure was measured using Comprehensive Lab Animal Monitoring System. At 22 weeks of age, an oral glucose tolerance test (OGTT) was performed, and using fasting glucose and insulin values, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was calculated as a surrogate measure of insulin resistance. At 30.5 weeks of age, blood and liver tissues were harvested. Liver antioxidant capacity, lipids and expression of genes involved in lipid metabolism (Cd36, Fabp1, Acaca, Fasn, Cpt1a, Srebf1) were measured. HFD increased adiposity (p < 0.001) and body weight (p < 0.001), both of which did not occur in the HS group. The animals fed HFD developed impaired fasting glucose, impaired glucose tolerance, and fasting hyperinsulinemia compared to control fed animals. Interestingly, HS animals demonstrated an improvement in fasting glucose and fasting insulin. Based on insulin release during OGTT and HOMA-IR, the supplement appeared to reduce the insulin resistance developed by HFD feeding. Supplementation increased hepatic glutathione content (p < 0.05) and reduced hepatic triglyceride accumulation (p < 0.001) regardless of diet; this was accompanied by altered gene expression (particularly of CPT-1). Our findings show that dietary micronutrient supplementation can reduce weight gain and adiposity, improve glucose metabolism, and improve hepatic antioxidant capacity and lipid metabolism in response to HFD intake.


2020 ◽  
Vol 45 (10) ◽  
pp. 1092-1098
Author(s):  
Soodabeh Aliashrafi ◽  
Mehrangiz Ebrahimi-Mameghani ◽  
Mohammad Asghari Jafarabadi ◽  
Lida Lotfi-Dizaji ◽  
Elnaz Vaghef-Mehrabany ◽  
...  

As there is limited and inconsistent evidence in potential role of vitamin D on insulin resistance and matrix metalloproteinases, this study aimed to examine the effect of vitamin D supplementation on glucose homeostasis, insulin resistance, and matrix metalloproteinases in obese subjects with vitamin D deficiency. A total of 44 participants with serum 25-hydroxyvitamin D (25(OH)D) level ≤ 50 nmol/L and body mass index (BMI) 30–40 kg/m2 were randomly allocated into receiving weight reduction diet with either 50 000 IU vitamin D3 pearl (n = 22) or placebo (n = 22) once weekly for 12 weeks. Primary outcomes were changes in fasting serum glucose (FSG), homeostasis model assessment of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and matrix metalloproteinases (MMPs). Secondary outcomes were changes in weight, BMI, 25(OH)D, calcium, phosphorous and parathyroid hormone (PTH). Sun exposure and dietary intakes were also assessed. Serum levels of 25(OH)D3 increased significantly with a simultaneous decrease in serum concentration of PTH in the vitamin D group. Weight, BMI, FSG, and MMP-9 decreased significantly in both groups, and there were significant differences in changes in weight, serum 25(OH)D3, PTH, and MMP-9 levels between the groups. Within- and between-groups analysis revealed no significant differences in serum calcium, phosphorous, serum insulin, HOMA-IR, QUICKI, and MMP-2 after intervention. Our results indicated that improvement in vitamin D status resulted in greater reductions in weight and MMP-9 during weight loss. These preliminary results are sufficient to warrant a bigger study group.


2016 ◽  
Vol 46 (15) ◽  
pp. 3219-3230 ◽  
Author(s):  
D. C. Chen ◽  
X. D. Du ◽  
G. Z. Yin ◽  
K. B. Yang ◽  
Y. Nie ◽  
...  

BackgroundSchizophrenia patients have a higher prevalence of type 2 diabetes mellitus with impaired glucose tolerance (IGT) than normals. We examined the relationship between IGT and clinical phenotypes or cognitive deficits in first-episode, drug-naïve (FEDN) Han Chinese patients with schizophrenia.MethodA total of 175 in-patients were compared with 31 healthy controls on anthropometric measures and fasting plasma levels of glucose, insulin and lipids. They were also compared using a 75 g oral glucose tolerance test and the homeostasis model assessment of insulin resistance (HOMA-IR). Neurocognitive functioning was assessed using the MATRICS Consensus Cognitive Battery (MCCB). Patient psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS).ResultsOf the patients, 24.5% had IGT compared with none of the controls, and they also had significantly higher levels of fasting blood glucose and 2-h glucose after an oral glucose load, and were more insulin resistant. Compared with those patients with normal glucose tolerance, the IGT patients were older, had a later age of onset, higher waist or hip circumference and body mass index, higher levels of low-density lipoprotein and triglycerides and higher insulin resistance. Furthermore, IGT patients had higher PANSS total and negative symptom subscale scores, but no greater cognitive impairment except on the emotional intelligence index of the MCCB.ConclusionsIGT occurs with greater frequency in FEDN schizophrenia, and shows association with demographic and anthropometric parameters, as well as with clinical symptoms but minimally with cognitive impairment during the early course of the disorder.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hui Wu ◽  
Michael Wu ◽  
Yi Chen ◽  
Carolyn A. Allan ◽  
David J. Phillips ◽  
...  

Aims. Activins A and B, and their binding protein, follistatin, regulate glucose metabolism and inflammation. Consequently, their role in type 2 diabetes (T2D) was examined.Methods. Blood was taken from fasted participants (34 males; 58 females; 50–75 years) with diabetes or during an oral glucose tolerance test (OGTT). Clinical parameters were assessed, and blood assayed for activins, follistatin, and C-reactive protein.Results. Serum levels of activin A (93.3 ± 27.0 pg/mL, mean ± SD), B (81.8 ± 30.8 pg/mL), or follistatin (6.52 ± 3.15 ng/mL) were not different (P>0.05) between subjects with normal OGTT (n=39), impaired glucose tolerance and/or fasting glucose (n=17), or T2D (n=36). However, activin A and/or activin B were positively correlated with parameters of insulin resistance and T2D, including fasting glucose (P<0.001), fasting insulin (P=0.02), glycated hemoglobin (P=0.003), and homeostasis model assessment of insulin resistance (HOMA-IR;P<0.001). Follistatin was positively correlated with HOMA-IR alone (P=0.01).Conclusions. These data indicate that serum measurements of activin A, B, or follistatin cannot discriminate risk for T2D in individual patients, but the activins display a positive relationship with clinical parameters of the disease.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Alexis Elias Malavazos ◽  
Emanuele Cereda ◽  
Federica Ermetici ◽  
Riccardo Caccialanza ◽  
Silvia Briganti ◽  
...  

“Lipid accumulation product” (LAP) is a continuous variable based on waist circumference and triglyceride concentration previously associated with insulin resistance. We investigated the accuracy of LAP in identifying oral glucose tolerance test (OGTT) abnormalities and compared it to the homeostasis model assessment of insulin resistance (HOMA-IR) in a population of overweight/obese outpatients presenting with nondiabetic fasting glucose. We studied 381 (male: 23%) adult (age: 18–70 years) overweight/obese Caucasians (body mass index: 36.9 ± 5.4 Kg/m2) having fasting plasma glucose < 7.0 mmol/L. OGTT was used to diagnose unknown glucose tolerance abnormalities: impaired glucose tolerance (IGT) and type-2 diabetes mellitus (T2-DM). According to OGTT 92, subjects had an IGT and 33 were diagnosed T2-DM. Logistic regression analysis detected a significant association for both LAP and HOMA-IR with single (IGT and T2-DM) and composite (IGT + T2-DM) abnormal glucose tolerance conditions. However, while the association with diabetes was similar between LAP and HOMA-IR, the relationship with IGT and composite outcomes by models including LAP was significantly superior to those including HOMA-IR (P=0.006andP=0.007, resp.). LAP seems to be an accurate index, performing better than HOMA-IR, for identifying 2-hour postload OGTT outcomes in overweight/obese patients with nondiabetic fasting glucose.


2019 ◽  
Vol 15 (5) ◽  
pp. 414-419 ◽  
Author(s):  
Zahra Mazloum Khorasani ◽  
Shokoufeh Bonakdaran ◽  
Hasan Pour Rafieie

Background: Diabetes Mellitus is one of the most common medical disorders in pregnancy. The possibility of vitamin D deficiency as a pathogenesis for impaired glucose tolerance tests show a probable role of vitamin D in insulin secretion and reduction of insulin resistance. This study was assigned to evaluate relation between serum vitamin D level and insulin resistance in Gestational Diabetes Mellitus (GDM). Methods: This cross sectional study was done throughout one year between 2015-2016 in GDM patients (age, 20-40 years). After history taking and physical examination, the laboratory tests including : Fasting Blood Sugar (FBS), Glucose Tolerance Test (GTT), calcium, phosphorous, parathormone, 25(OH) vitamin D, insulin, HbA1C, TG, LDL, HDL were performed for all patients. Insulin resistance was calculated according to HOMA-IR formula. Vitamin D level was compared between patients with and without insulin resistance. Results: This research was performed in 93 GDM patients with average age (30.3 ± 5.6). Thirty eight patients with insulin resistance and 55 patients without insulin resistance were detected. The prevalence of vitamin D deficiency was 91.4% in all patients. There was no significant difference in vitamin D levels between insulin resistant and non insulin resistant group (P-value=0.51). : In all variable parameters, only FBS and triglyceride level in insulin resistant group were more than non insulin resistant group (P-value<0.05). : Obtained results showed not significant relationship between vitamin D deficiency and insulin resistance in GDM patients.


2009 ◽  
Vol 161 (4) ◽  
pp. 575-582 ◽  
Author(s):  
E Wehr ◽  
S Pilz ◽  
N Schweighofer ◽  
A Giuliani ◽  
D Kopera ◽  
...  

ObjectivesWomen with polycystic ovary syndrome (PCOS) frequently suffer from metabolic disturbances, in particular from insulin resistance. Accumulating evidence suggests that vitamin D deficiency may contribute to the development of the metabolic syndrome (MS). Hence, the aim of our study was to investigate the association of 25(OH)D levels and the components of the MS in PCOS women.Methods25(OH)D levels were measured by means of ELISA in 206 women affected by PCOS. Metabolic, endocrine, and anthropometric measurements and oral glucose tolerance tests were performed.ResultsThe prevalence of insufficient 25(OH)D levels (<30 ng/ml) was 72.8% in women with PCOS. PCOS women with the MS had lower 25(OH)D levels than PCOS women without these features (17.3 vs 25.8 ng/ml respectively; P<0.05). In multivariate regression analysis including 25(OH)D, season, body mass index (BMI), and age, 25(OH)D and BMI were independent predictors of homeostatic model assessment-insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI; P<0.05 for all). In binary logistic regression analyses, 25(OH)D (OR 0.86, P=0.019) and BMI (OR 1.28, P<0.001) were independent predictors of the MS in PCOS women. We found significantly negative correlations of 25(OH)D levels with BMI, waist circumference, waist-to-hip ratio, systolic and diastolic blood pressure, fasting and stimulated glucose, area under the glucose response curve, fasting insulin, HOMA-IR, HOMA-β, triglycerides, and quotient total cholesterol/high-density lipoprotein (HDL) and positive correlations of 25(OH)D levels with QUICKI and HDL (P<0.05 for all).ConclusionWe demonstrate that low 25(OH)D levels are associated with features of the MS in PCOS women. Large intervention trials are warranted to evaluate the effect of vitamin D supplementation on metabolic disturbances in PCOS women.


2006 ◽  
Vol 155 (1) ◽  
pp. 73-78 ◽  
Author(s):  
B Steffin ◽  
B Gutt ◽  
M Bidlingmaier ◽  
C Dieterle ◽  
F Oltmann ◽  
...  

Object: Treatment with somatostatin analogues (SA) not only inhibits GH secretion but may also impair insulin secretion. In order to evaluate the influence of SA on glucose metabolism, we investigated insulin resistance (IR) and β-cell function, using the recommended combination of homeostatic model assessment of IR (HOMA-IR) and β-cell function (HOMA-β). Design and methods: This is a prospective, cross-sectional study. We measured fasting insulin, blood glucose and IGF-I. Insulin and blood glucose measurements were taken 120 min after an oral glucose tolerance test with 75 g glucose. We studied 51 patients (27 female/24 male, age 54 years (20–75)). Eighteen patients were on Lanreotide Autogel (LA) treatment, 33 had no medical treatment. GH-levels of more than 2.5 ng/ml was reached by 59% of the patients, 74.5% had normal IGF-I levels. Results: We found no significant influence of disease activity on HOMA-IR and HOMA-β. In the 33 of 51 subjects without any drug treatment, median HOMA-β was 170.4% (36.0–624.0%). In contrast, in the 18 patients on LA treatment, median HOMA-β was found to be significantly lower (84.2% (36.5–346.2%); P = 0.001). Despite this, there was no difference in HOMA-IR in both groups (2.4 (0.7–8.4) vs 2.3 (0.7–6.1); P < 0.001) despite similar insulin values. Conclusion: In conclusion, we found that LA decreases β-cell function significantly without affecting IR. Therefore, we think that insulin secretagogues are probably more effective in the treatment of diabetes mellitus in acromegalic patients on LA therapy than insulin sensitizers.


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