Magnesium intake, insulin resistance and markers of endothelial function among women

Abstract Objective: We investigated the association of dietary Mg intake with insulin resistance and markers of endothelial function among Iranian women. Design: A cross-sectional study. Setting: Usual dietary intakes were assessed using a validated FFQ. Dietary Mg intake was calculated by summing up the amount of Mg in all foods. A fasting blood sample was taken to measure serum concentrations of glycemic indices (fasting plasma glucose and insulin) and endothelial function markers (E-selectin, soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1). Insulin resistance and sensitivity were estimated using the Homeostasis Model Assessment-Insulin Resistance (HOMA-IR), Homeostasis Model Assessment β-cell function (HOMA-β) and quantitative insulin sensitivity check index (QUICKI). Participants: Iranian female nurses (n 345) selected by a multistage cluster random sampling method. Results: The Mg intake across energy-adjusted quartiles was 205 (se 7), 221·4 (se 8), 254·3 (se 7) and 355·2 (se 9) mg/d, respectively. After adjustments for potential confounders, QUICKI level was significantly different across quartiles of Mg intake (Q1: 0·34 (se 0·02), Q2: 0·36 (se 0·01), Q3: 0·40 (se 0·01), and Q4: 0·39 (se 0·02), P = 0·02); however, this association disappeared after considering markers of endothelial function, indicating that this relation might be mediated through endothelial dysfunction. After controlling for all potential confounders, Mg intake was inversely, but not significantly, associated with serum concentrations of sICAM (Q1: 239 (se 17), Q2: 214 (se 12), Q3: 196 (se 12), and Q4: 195 (se 17), P = 0·29). There was no other significant association between dietary Mg intake and other indicators of glucose homoeostasis or endothelial markers. Conclusions: Higher dietary Mg intake was associated with better insulin sensitivity in Iranian females. This linkage was mediated through reduced endothelial dysfunction.

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Association of endothelial dysfunction with incident prediabetes, type 2 diabetes and related traits: the KORA F4/FF4 study

BMJ Open Diabetes Research & Care ◽

10.1136/bmjdrc-2020-001321 ◽

2020 ◽

Vol 8 (1) ◽

pp. e001321

Author(s):

Marie-Theres Huemer ◽

Cornelia Huth ◽

Florian Schederecker ◽

Stefanie J Klug ◽

Christa Meisinger ◽

...

Keyword(s):

Insulin Resistance ◽

Type 2 Diabetes ◽

Endothelial Dysfunction ◽

Endothelial Function ◽

Fasting Glucose ◽

Model Assessment ◽

Fasting Insulin ◽

Homeostasis Model Assessment

IntroductionPeripheral arterial tonometry (PAT) is an operator-independent and non-invasive measurement method to assess microvascular endothelial function in the fingertips. PAT-derived measures of endothelial function were associated with type 2 diabetes in cross-sectional studies. However, longitudinal studies are lacking. The study aims to investigate the association of two PAT-derived endothelial function parameters reactive hyperemia index (RHI) and mean baseline amplitude (MBA) with follow-up glucose and insulin parameters and the development of (pre)diabetes and type 2 diabetes.Research design and methodsThe study included 673 participants initially without diabetes (328 men and 345 women) aged 52–71 years from the prospective population-based Cooperative Health Research in the Region of Augsburg F4/FF4 cohort study conducted in Southern Germany (baseline examination F4: 2006–2008; follow-up FF4: 2013–2014). An oral glucose tolerance test was performed at baseline and follow-up to define type 2 diabetes, prediabetes, fasting glucose, fasting insulin, 2-hour glucose, homeostasis model assessment of insulin resistance (HOMA-IR), homeostasis model assessment of beta-cell function and hemoglobin A1c.ResultsIn multivariable adjusted logistic/linear regression models, a 1 SD increase in baseline RHI was inversely associated with incident type 2 diabetes (OR 0.69 (95% CI 0.48 to 0.97)) as well as with fasting insulin (β −0.069 (95% CI −0.131 to −0.007)) and HOMA-IR (β −0.072 (95% CI −0.133 to −0.010)) at follow-up in participants with initial normoglycemia. A 1 SD increase in baseline MBA was positively associated with incident (pre)diabetes (OR 1.62 (95% CI 1.25 to 2.11)) and fasting glucose (β 0.096 (95% CI 0.047 to 0.146)) at follow-up in participants with initial normoglycemia.ConclusionsMicrovascular endothelial dysfunction seems to be involved in the development of early derangements in glucose metabolism and insulin resistance and could thereby trigger the development of prediabetes and type 2 diabetes.

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Assessing the test–retest repeatability of insulin resistance measures: Homeostasis model assessment 2 and oral glucose insulin sensitivity

Journal of Insulin Resistance ◽

10.4102/jir.v2i1.27 ◽

2017 ◽

Vol 1 (1) ◽

Cited By ~ 1

Author(s):

Catherine A.P. Crofts ◽

Mark C. Wheldon ◽

Caryn Zinn ◽

Xiaomiao Lan-Pidhainy ◽

Thomas M.S. Wolever ◽

...

Keyword(s):

Insulin Resistance ◽

Insulin Sensitivity ◽

Cell Function ◽

Small Population ◽

Oral Glucose ◽

Model Assessment ◽

Repeatability Coefficient ◽

Homeostasis Model Assessment ◽

Data Set ◽

Subsequent Test

Background: Insulin resistance is commonly assessed using the homeostasis model assessment (HOMA) variants. HOMA is potentially insensitive to change because of its high coefficient of variation. The repeatability coefficient is an alternative means of assessing test repeatability. To be confident of clinical change, rather than biological variation, a subsequent test needs to differ from the former by more than the repeatability coefficient using the equation.Test 1 = Test 2 ± repeatability coefficient.The repeatability coefficients for measures of insulin resistance are unknown.Aim: To compare the repeatability coefficient of HOMA2 variants (Beta-cell function [%B], insulin sensitivity [%S], insulin resistance [IR]) to a dynamic measure of insulin resistance, and the oral glucose insulin sensitivity (OGIS) test.Setting: The raw data from a previously used data set were reanalysed.Methods: Glycaemic and insulinaemic tests were performed on 32 men and women both with (n = 10) and without type 2 diabetes (n = 22). From these data, eight fasting tests and three 50-g oral glucose tolerance tests were used to calculate HOMA2 and OGIS. The methods of Bland and Altman assessed repeatability.Results: Repeatability coefficients for all participants for the HOMA2 %B, %S and IR variants were 72.91, 189.75 and 0.9, which equates to 89%, 135% and 89% of their respective grand means. By contrast, OGIS had a repeatability coefficient of 87.13, which equates to 21% of the grand mean.Conclusion: Because of the high repeatability coefficient relative to the grand mean, use of HOMA2 measures for assessing insulin resistance in small population studies should be reconsidered.

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Leptin Levels, β-Cell Function, and Insulin Sensitivity in Families with Congenital and Acquired Generalized Lipoatropic Diabetes1

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.83.2.4567 ◽

1998 ◽

Vol 83 (2) ◽

pp. 503-508

Author(s):

Victor C. Pardini ◽

Ivana M. N. Victória ◽

Selma M. V. Rocha ◽

Danielle G. Andrade ◽

Aline M. Rocha ◽

...

Keyword(s):

Insulin Sensitivity ◽

Temporal Relationship ◽

Cell Function ◽

Model Assessment ◽

Homeostasis Model Assessment ◽

Β Cell ◽

Insulin Levels ◽

Β Cell Function ◽

Plasma Leptin ◽

Specific Insulin

Lipoatropic diabetes (LD) designates a group of syndromes characterized by diabetes mellitus with marked insulin resistance and either a localized or generalized absence of adipose tissue. In this study, we evaluated plasma leptin levels in subjects with congenital generalized lipoatropic diabetes (CGLD, n = 11) or acquired generalized lipoatropic diabetes (AGLD, n = 11), and assessed correlations between leptin levels and estimations of insulin secretion and insulin sensitivity using homeostasis model assessment (HOMA). Leptin levels were 0.86 ± 0.32, 1.76 ± 0.78, and 6.9 ± 4.4 ng/mL in subjects with CGLD, AGLD, and controls (n = 19), respectively (ANOVA P < 0.0001). Specific insulin levels were 154 ± 172, 177 ± 137 and 43 ± 22 pmol/L, respectively (P < 0.0001). Insulin sensitivity was significantly decreased in both groups with LD (P< 0.0001), whereas HOMA β-cell function was not significantly different when compared with controls. Leptin levels were significantly correlated with body mass index, insulin levels, and HOMA β-cell function, and inversely correlated with insulin sensitivity in control subjects but not in subjects with generalized LD. In conclusion, decreased leptin levels were observed in subjects with generalized LD, with a trend towards lower levels in the acquired than in the congenital form (P = 0.06). The temporal relationship between the decrease in leptin levels and the development of lipoatrophy should be investigated in at-risk young relatives of subjects with the acquired forms to assess the usefulness of leptin levels as a marker of lipoatrophy.

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Uric acid lowering improves insulin sensitivity and lowers blood pressure: a meta-analysis of randomized parallel-controlled clinical trials

African Health Sciences ◽

10.4314/ahs.v21i1.13 ◽

2021 ◽

Vol 21 (1) ◽

pp. 82-95

Author(s):

Qunchuan Zong ◽

Guanyi Ma ◽

Tao Wang

Keyword(s):

Blood Pressure ◽

Uric Acid ◽

Insulin Sensitivity ◽

Cell Function ◽

Meta Analysis ◽

Model Assessment ◽

Controlled Clinical Trials ◽

Homeostasis Model Assessment ◽

Β Cell ◽

Β Cell Function

Objectives: This meta-analysis aimed to investigate whether uric acid lowering treatment can improve β-cell function and insulin sensitivity. Methods: PubMed, Cochrane Library, EMBASE and China Biology Medicine were searched up to March 1, 2020. Rand- omized controlled clinical trials of urate lowering therapy in hyperuricemia patients were included in meta-analysis. Effect size was estimated as mean difference with 95% confidence interval (CI). Results: Our search yielded 7 eligible trials with 503 participants. This meta-analysis showed that uric acid-lowering thera- py decreased fasting insulin -1.43 μIU/ml (weighted mean differences (WMD, 95% CI -2.78 to -0.09), homeostasis model assessment of insulin resistance -0.65 (WMD, 95% CI -1.05 to -0.24), systolic blood pressure -2.45 mm Hg (WMD, 95%CI -4.57 to -0.33) and diastolic blood pressure -3.41 mm Hg (WMD, 95%CI -3.87 to -2.95). However, the treatment had no significant effect on fasting plasma glucose (WMD -0.19 mmol/L, 95%CI -0.42 to 0.05), homeostasis model assessment of β-cell function index (WMD -0.02, 95%CI -0.28 to 0.24), total cholesterol (WMD 0.18 mg/dl; 95%CI, -1.39 to 1.75) and triglyceride (WMD 3.15 mg/dl, 95% CI -9.83 to 16.14). Conclusion: Uric acid-lowering therapies might improve insulin sensitivity and lower blood pressure, but had no significant effect on HOMA-β and serum lipids. Keywords: Hyperuricemia; uric acid lowering treatment; β-cell function; insulin sensitivity.

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PPARαAgonist Fenofibrate Reduced the Secreting Load ofβ-Cells in Hypertriglyceridemia Patients with Normal Glucose Tolerance

PPAR Research ◽

10.1155/2016/6232036 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7

Author(s):

Jia Liu ◽

Rui Lu ◽

Ying Wang ◽

Yanjin Hu ◽

Yumei Jia ◽

...

Keyword(s):

Insulin Resistance ◽

Glucose Tolerance ◽

Cell Function ◽

Density Lipoprotein ◽

Normal Glucose Tolerance ◽

Model Assessment ◽

Homeostasis Model Assessment ◽

Cell Dysfunction ◽

Fenofibrate Treatment ◽

Normal Glucose

Hypertriglyceridemia is an important risk factor associated with insulin resistance andβ-cell dysfunction. This study investigated the effects of hypertriglyceridemia and fenofibrate treatment on insulin sensitivity andβ-cell function in subjects with normal glucose tolerance. A total of 1974 subjects with normal glucose tolerance were divided into the normal TG group (NTG group,n=1302) and hypertriglyceridemia group (HTG group,n=672). Next, 92 patients selected randomly from 672 patients with hypertriglyceridemia were assigned to a 24-week fenofibrate treatment. The HTG group had increased waist circumference (WC), body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR), and homeostasis model assessment ofβ-cell function (HOMA-β) and decreased high-density lipoprotein cholesterol (HDL-C) compared with the NTG group (allP<0.01). The 24-week fenofibrate treatment significantly decreased the WC, BMI, TG, HOMA-IR, and HOMA-βlevels and increased the HDL-C levels in the patients with hypertriglyceridemia (WC, BMI, and HOMA-IR:P<0.05; TG, HDL-C, and HOMA-β:P<0.01). The fenofibrate treatment significantly alleviated insulin resistance and reduced the secreting load ofβ-cells in the hypertriglyceridemia patients with normal glucose tolerance.

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Women at altitude: short-term exposure to hypoxia and/or α1-adrenergic blockade reduces insulin sensitivity

Journal of Applied Physiology ◽

10.1152/jappl.2001.91.2.623 ◽

2001 ◽

Vol 91 (2) ◽

pp. 623-631 ◽

Cited By ~ 66

Author(s):

Barry Braun ◽

Paul B. Rock ◽

Stacy Zamudio ◽

Gene E. Wolfel ◽

Robert S. Mazzeo ◽

...

Keyword(s):

Insulin Resistance ◽

Insulin Sensitivity ◽

Cell Function ◽

Sensitivity Index ◽

Adrenergic Blockade ◽

Model Assessment ◽

Plasma Epinephrine ◽

Short Term ◽

Short Term Exposure ◽

Adrenergic Antagonist

After short-term exposure to high altitude (HA), men appear to be less sensitive to insulin than at sea level (SL). We hypothesized that the same would be true in women, that reduced insulin sensitivity would be directly related to the rise in plasma epinephrine concentrations at altitude, and that the addition of α-adrenergic blockade would potentiate the reduction. To test the hypotheses, 12 women consumed a high-carbohydrate meal at SL and after 16 h at simulated 4,300-m elevation (HA). Subjects were studied twice at each elevation: once with prazosin (Prz), an α1-adrenergic antagonist, and once with placebo (Pla). Mathematical models were used to assess insulin resistance based on fasting [homeostasis model assessment of insulin resistance (HOMA-IR)] and postprandial [composite model insulin sensitivity index (C-ISI)] glucose and insulin concentrations. Relative to SL-Pla (HOMA-IR: 1.86 ± 0.35), insulin resistance was greater in HA-Pla (3.00 ± 0.45; P < 0.05), SL-Prz (3.46 ± 0.51; P < 0.01), and HA-Prz (2.82 ± 0.43; P < 0.05). Insulin sensitivity was reduced in HA-Pla (C-ISI: 4.41 ± 1.03; P < 0.01), SL-Prz (5.73 ± 1.01; P < 0.05), and HA-Prz (4.18 ± 0.99; P < 0.01) relative to SL-Pla (8.02 ± 0.92). Plasma epinephrine was significantly elevated in HA-Pla (0.57 ± 0.08 ng/ml; P < 0.01), SL-Prz (0.42 ± 0.07; P < 0.05), and HA-Prz (0.82 ± 0.07; P < 0.01) relative to SL-Pla (0.28 ± 0.04), but correlations with HOMA-IR, HOMA-β-cell function, and C-ISI were weak. In women, short-term exposure to simulated HA reduced insulin sensitivity compared with SL. The change does not appear to be directly mediated by a concurrent rise in plasma epinephrine concentrations.

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Estimates of Insulin Secretory Function in Apparently Healthy Volunteers Vary as a Function of How the Relevant Variables Are Quantified

Clinical Chemistry ◽

10.1373/clinchem.2010.152744 ◽

2011 ◽

Vol 57 (4) ◽

pp. 627-632 ◽

Cited By ~ 5

Author(s):

Barry R Johns ◽

Fahim Abbasi ◽

Gerald M Reaven

Keyword(s):

Insulin Resistance ◽

Insulin Secretion ◽

Plasma Glucose ◽

Insulin Action ◽

Cell Function ◽

Model Assessment ◽

Pancreatic Β Cell ◽

Homeostasis Model Assessment ◽

Β Cell ◽

Β Cell Function

BACKGROUND Several surrogate estimates have been used to define relationships between insulin action and pancreatic β-cell function in healthy individuals. Because it is unclear how conclusions about insulin secretory function depend on specific estimates used, we evaluated the effect of different approaches to measurement of insulin action and secretion on observations of pancreatic β-cell function in individuals whose fasting plasma glucose (FPG) was <7.0 mmol/L (126 mg/dL). METHODS We determined 2 indices of insulin secretion [homeostasis model assessment of β-cell function (HOMA-β) and daylong insulin response to mixed meals], insulin action [homeostasis model assessment of insulin resistance (HOMA-IR) and steady-state plasma glucose (SSPG) concentration during the insulin suppression test], and degree of glycemia [fasting plasma glucose (FPG) and daylong glucose response to mixed meals] in 285 individuals with FPG <7.0 mmol/L. We compared the relationship between the 2 measures of insulin secretion as a function of the measures of insulin action and degree of glycemia. RESULTS Assessment of insulin secretion varied dramatically as a function of which of the 2 methods was used and which measure of insulin resistance or glycemia served as the independent variable. For example, the correlation between insulin secretion (HOMA-β) and insulin resistance varied from an r value of 0.74 (when HOMA-IR was used) to 0.22 (when SSPG concentration was used). CONCLUSIONS Conclusions about β-cell function in nondiabetic individuals depend on the measurements used to assess insulin action and insulin secretion. Viewing estimates of insulin secretion in relationship to measures of insulin resistance and/or degree of glycemia does not mean that an unequivocal measure of pancreatic β-cell function has been obtained.

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