Martha Rodríguez-Morán

The Product of Triglycerides and Glucose, a Simple Measure of Insulin Sensitivity. Comparison with the Euglycemic-Hyperinsulinemic Clamp

CONTEXT To meet the worldwide challenge of emerging diabetes, accessible and inexpensive tests to identify insulin resistance are needed. OBJECTIVE To evaluate the sensitivity and specificity of the product of fasting, we compared the triglycerides and glucose (TyG) index, a simple measure of insulin resistance, with the euglycemic-hyperinsulinemic clamp test. DESIGN AND SETTING We conducted a cross-sectional study of the general population and outpatients of the Internal Medicine Department at the Medical Unit of High Specialty of the Specialty Hospital at the West National Medical Center in Guadalajara, Mexico. PATIENTS Eleven nonobese healthy subjects, 34 obese normal glucose tolerance individuals, 22 subjects with prediabetes, and 32 diabetic patients participated in the study. INTERVENTION We performed a euglycemic-hyperinsulinemic clamp test. MAIN OUTCOME MEASURES Sensitivity and specificity of the TyG index [Ln(fasting triglycerides) (mg/dl) x fasting glucose (mg/dl)/2] were measured, as well as the area under the curve of the receiver operating characteristic scatter plot and the correlation between the TyG index and the total glucose metabolism (M) rates. RESULTS Pearsons correlation coefficient between the TyG index and M rates was -0.681 (P < 0.005). Correlation between the TyG index and M rates was similar between men (-0.740) and women (-0.730), nonobese (-0.705) and obese (-0.710), and nondiabetic (-0.670) and diabetic (-0.690) individuals. The best value of the TyG index for diagnosis of insulin resistance was 4.68, which showed the highest sensitivity (96.5%) and specificity (85.0%; area under the curve + 0.858). CONCLUSIONS The TyG index has high sensitivity and specificity, suggesting that it could be useful for identification of subjects with decreased insulin sensitivity.

Lipid- and Glucose-Lowering Efficacy of Plantago Psyllium in Type II Diabetes

The beneficial effect of dietary fiber in the management of type II diabetes is still controversial and has not been totally demonstrated. The purpose of this study was to determine the plasma-lowering effects of 5 g t.i.d. of Plantago Psyllium, as an adjunct to dietary therapy, on lipid and glucose levels, in patients with type II diabetes. Patients were randomly selected from an outpatient clinic of primary care to participate in a double-blind placebo-controlled study in which Plantago Psyllium or placebo was given in combination with a low fat diet. One hundred twenty-five subjects were included in the study that consisted in a 6-week period of diet counseling followed by a 6-week treatment period. Fasting plasma glucose, total plasma cholesterol, LDL cholesterol, HDL cholesterol and triglyceride levels were measured every 2 weeks. The test products (Psyllium or placebo) were supplied to subjects in identically labeled foil packets containing a 5-g dose of product, to consume three doses per day (of 5 g each one), before regular meals. There was an excellent tolerance to Psyllium, without significant adverse effects. No significant changes were observed in the patients weight for both groups (not significant). Fasting plasma glucose, total cholesterol, LDL cholesterol, and triglycerides levels, showed a significant reduction (p < 0.05), whereas HDL cholesterol increased significantly (p < 0.01) following Psyllium treatment. Our results show that 5 g t.i.d. of Psyllium is useful, as an adjunct to dietary therapy, in patients with type II diabetes, to reduce plasma lipid and glucose levels, resolving the compliance conflict associated with the ingest of a great amount of fiber in customary diet.

The Product of Fasting Glucose and Triglycerides As Surrogate for Identifying Insulin Resistance in Apparently Healthy Subjects

BACKGROUND Because the insulin test is expensive and is not available in most laboratories in the cities of undeveloped countries, we tested whether the product of fasting triglycerides and glucose levels (TyG) is a surrogate for estimating insulin resistance compared with the homeostasis model assessment of insulin resistance (HOMA-IR) index. METHODS We performed a population-based cross-sectional study. Sampling strategy was based on a randomized two-stage cluster sampling procedure. Only apparently healthy subjects, men and nonpregnant women aged 18-65 years, with newly diagnosed impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or IFG + IGT were enrolled. Renal disease, malignancy, and diabetes were exclusion criteria. Sensitivity, specificity, predictive values, and the probability of disease given a positive test were calculated. The optimal TyG index for estimating insulin resistance was established using a receiver operating characteristic scatter plot analysis. RESULTS A total of 748 apparently healthy subjects aged 41.4 +/- 11.2 years were enrolled. Insulin resistance was identified in 241 (32.2%) subjects (HOMA-IR index 4.4 +/- 1.6). New diagnoses of IFG, IGT, and IFG + IGT were established in 145 (19.4%), 54 (7.2%), and 75 (10.0%) individuals. respectively. The best TyG index for diagnosis of insulin resistance was Ln 4.65, which showed the highest sensitivity (84.0%) and specificity (45.0%) values. The positive and negative predictive values were 81.1% and 84.8%, and the probability of disease, given a positive test, was 60.5%. CONCLUSIONS The TyG index could be useful as surrogate to identify insulin resistance in apparently healthy subjects.

Hypomagnesemia, oxidative stress, inflammation, and metabolic syndrome

Although hypomagnesemia, oxidative stress, and inflammation are involved in the pathogenesis of cardiovascular diseases, there is not a previous description concerning their potential interaction; thus, the aim of this study was to examine the relationship between metabolic syndrome (MetS), hypomagnesemia, inflammation, and oxidative stress.

Increased Levels of C-Reactive Protein in Noncontrolled Type II Diabetic Subjects

Type II diabetes is an hemorheological disease in which hyperglycemia increases the shear stress contributing to inflammation and dysfunction of endothelium. The purpose of this study was to identify the relationship between serum C-reactive protein and glucose levels in noncontrolled type II diabetic subjects. A cross-sectional study was conducted, including 62 noncontrolled type II diabetic subjects that were assigned to two groups. One group was patients with acute diarrhea or urinary tract infection and the other group was diabetic subjects who were infectious-disease free. Sixty-two subjects without diabetes constituted the respective control groups. Heart failure, other acute febrile illnesses, asymptomatic infection, renal, hepatic, malignant or chronic inflammatory illness, and macrovascular disease were considered as exclusion criteria. Laboratory measurements were performed. Thirty (96.7%) and 29 (93.5%) diabetic patients in the groups with and without infectious disease, and 28 (90.3%) control subjects with infectious disease had elevated C-reactive protein levels (> or =10 mg/L). In contrast, healthy control subjects did not have elevated serum C-reactive protein levels. Multiple regression analysis showed a significant association between C-reactive protein levels and hyperglycemia (Odds ratio = 7.4; IC95% 2.3-11.2). This study show that hyperglycemia is a related factor to the increase of serum CRP levels in noncontrolled type II diabetic subjects.

Hypomagnesemia is linked to low serum HDL-cholesterol irrespective of serum glucose values.

Hypomagnesemia is common in diabetic subjects, and is especially common in poorly controlled diabetes, suggesting that diabetes low serum magnesium status is osmotic diuresis-dependent. To assess the relationship between serum magnesium and HDL-cholesterol concentration adjusted by serum glucose values. We assessed the serum magnesium levels of 50 controlled (HbA(1c)</=7.5% and FPG<126 mg/dl), 110 non-controlled (HbA(1c)>7.5% and FPG>/=126 mg/dl) type II diabetic patients, 40 subjects with impaired fasting glucose (IFG) (FPG>/=110 mg/dl and <126 mg/dl) and 190 healthy volunteers (FPG<110 mg/dl). Healthy volunteers were required to have normal blood pressure and normal laboratory tests. Subjects in the groups included were matched by age and body mass index (BMI). The average of diabetes duration was of 11.4+/-6.6, and 10.9+/-6.2 years, P=NS, for the controlled and non-controlled diabetic patients, respectively. Thirty (60.0%) controlled diabetic subjects, 58 (52. 7%) non-controlled diabetic patients, 21 (52.5%) subjects with IFG, and 39 (20.5%) healthy volunteers had serum magnesium levels </=1.7 mg/l. Serum HDL-cholesterol value showed significant graded increase with serum magnesium levels irrespective of glucose values. Results of this study suggest that hypomagnesemia by an etiopathogenic pathway glycemia independent seems to be involved to decrease HDL-cholesterol.

Hypomagnesaemia and risk for metabolic glucose disorders: a 10‐year follow‐up study

Background   Although several lines of evidence suggest that hypomagnesaemia is a risk factor for developing type 2 diabetes, there are no studies regarding the association between hypomagnesaemia and the risk for developing impaired fasting glucose (IFG) or impaired glucose tolerance (IGT). Our objective was to examine the association between serum magnesium levels and the risk for developing IFG, IGT and type 2 diabetes.

Consumption of soft drinks with phosphoric acid as a risk factor for the development of hypocalcemia in children: A case-control study

A comparison of 57 cases (in children with serum calcium concentration < 2.2 mmol/L) and 171 controls (in children with serum calcium level > or = 2.2 mmol/L) was carried out to assess whether the intake of at least 1.5 L/wk of soft drinks containing phosphoric acid is a risk factor for the development of hypocalcemia. A significant association was found: odds ratio = 5.27; 95% confidence interval, 3.17 to 8.75; p < 0.001. The hypothesis of a causal relationship between intake of phosphoric acid-containing soft drinks and hypocalcemia warrants further investigation.

Proteinuria Is an Independent Risk Factor for Ischemic Stroke in Non–Insulin-Dependent Diabetes Mellitus

BACKGROUND AND PURPOSE Proteinuria is an independent risk factor for cardiovascular disease in patients with NIDDM. The aim of this study was to assess the relationship between proteinuria and ischemic stroke in subjects with NIDDM, and to determine whether proteinuria is an independent risk factor for stroke. METHODS We performed a case-control study of 59 diabetic patients with first-ever ischemic stroke due to thrombotic arterial occlusion, who were considered cases, and 180 diabetic patients without stroke, matched by gender, age, and diabetes duration, as a control group. WHO criteria for verified definite or possible stroke were used to ascertain the diagnosis of stroke. For the purpose of this study proteinuria was defined as a 24-hour urinary protein excretion rate of >/=20 and <200 microg/min. Risk factors included were smoking, blood pressure, body mass index, serum total cholesterol, hyperglycemia, and proteinuria. RESULTS Subjects with stroke had higher proteinuria proportion and systolic and diastolic blood pressures. Both frequency of antihypertensive treatment and antihypertensive drugs used were similar among subjects with and without stroke. In multivariate logistic regression analysis, the ORs and 95% CIs for the variables identified as risk factors for stroke were as follows: systolic pressure (OR 3.10; 95% CI 3.01 to 4.21; P=0.03); diastolic pressure (OR 3.30; 95% CI 1.04 to 4.48; P<0.0001); fasting glucose >/=11.1 mmol (OR 1.82; 905% CI 1.4 to 3.8; P=0.04), HbA1c >/=9.5% (OR 1.7; 95% CI 1.3 to 5.1; P<0.01), and proteinuria (OR 3.23; 95% CI 1.06 to 4.36; P<0.0001). CONCLUSIONS Our case-control study gives evidence that proteinuria is an independent risk factor for ischemic stroke in patients with NIDDM.

Magnesium improves the beta‐cell function to compensate variation of insulin sensitivity: double‐blind, randomized clinical trial

Eur J Clin Invest 2011; 41 (4): 405–410