Francisco J. Gómez-Pérez

High Adiponectin Concentrations Are Associated with the Metabolically Healthy Obese Phenotype

CONTEXT In the ob/ob mice, keeping adiponectin concentrations in the physiological range (through overexpression of this gene in the adipose tissue) results in expansion of fat mass and protection against metabolic co-morbidities. OBJECTIVE The aim of the study was to test in humans whether plasma adiponectin levels, similar to those found in lean subjects, are associated with the metabolically healthy obese phenotype. DESIGN AND SETTING A cross-sectional analysis was performed of a cohort of obese and nonobese subjects aged 18-70 yr. A medical history was taken, and glucose, plasma lipids, and total adiponectin were measured. PARTICIPANTS We studied 189 men and 527 women. The majority were obese (n = 470, 65.6%). The metabolically healthy obese phenotype was found in 38 men and 133 women. This is defined as a body mass index (BMI) above 30 kg/m(2) plus high-density lipoprotein cholesterol of at least 40 mg/dl in the absence of type 2 diabetes and arterial hypertension. RESULTS Twenty percent of the cases with a BMI above 40 kg/m(2) had adiponectin concentrations above the median value of normal BMI subjects. Adiponectin levels above 12.49 mg/liter in obese women (odds ratio, 3.02; 95% confidence interval, 1.95-4.67; P < 0.001) and above 8.07 mg/liter in obese men (odds ratio, 2.14; 95% confidence interval, 1.1-4.06; P = 0.01) increased the probability of being metabolically healthy. The association remained significant (beta, 0.673 +/- 0.205, P < 0.001) in a logistic regression model (r(2) = 0.25, P < 0.001) after controlling for the confounding effect of age, insulin, and waist circumference. CONCLUSIONS Certain obese individuals have adiponectin levels similar to those found in normal BMI subjects; this is associated with the metabolically healthy obese phenotype.

TSH and free thyroxine concentrations are associated with differing metabolic markers in euthyroid subjects

OBJECTIVE To examine the association between thyroid function and the components of the metabolic syndrome and insulin resistance in an Hispanic population. DESIGN Cross-sectional study. METHODS Subjects with no history of thyroid disease or diabetes were included. Thyroid function was stratified as euthyroid or subclinical hypothyroidism (SCH) status and subsequently by free thyroxine (FT(4)) and TSH tertiles. The association of the metabolic syndrome components (defined by 2004 Adult Treatment Panel III criteria) and insulin resistance with thyroid status, TSH, and FT(4) were examined. RESULTS A total of 3148 subjects were analyzed. The prevalence of SCH was 8.3%. The prevalence of the metabolic syndrome was similar in euthyroid and SCH patients (31.6 vs 32.06%, P=0.89). Total cholesterol was higher in patients with SCH (5.51+/-1.19 vs 5.34+/-1.05 mmol/l, P<0.032). Serum TSH values showed a positive correlation (adjusted for age and sex) with total cholesterol, triglycerides, and waist circumference. In contrast, FT(4) showed a positive correlation with high-density lipoprotein cholesterol, and an inverse correlation with waist circumference, insulin, and HOMA-IR. CONCLUSION SCH is not associated with an increased risk for the metabolic syndrome (as conceived as a diagnostic category defined by the National Cholesterol, Education Program, Adult Treatment Panel III criteria). Despite this, low thyroid function (even in the euthyroid state) predisposes to higher cholesterol, glucose, insulin, and HOMA-IR levels. The combined use of TSH and FT(4), compared with the assessment based on only FT(4), is a more convenient approach to evaluate the association between thyroid function and metabolic variables.

Nortriptyline and fluphenazine in the symptomatic treatment of diabetic neuropathy. A double-blind cross-over study

A controlled clinical trial on the efficacy of a nortriptyline-fluphenazine combination was carried out in patients with painful diabetic polyneuropathy. A visual analog scale was used to evaluate the relief of pain or paresthesia. Significant relief of both pain and paresthesia was obtained with this combination. The differences were statistically significant. Side effects were frequent but not usually severe enough to lead to cessation of these medications.

The FTO gene is associated with adulthood obesity in the Mexican population.

Common polymorphisms in the fat mass and obesity‐associated gene (FTO) have shown strong association with obesity in several populations. In the present study, we explored the association of FTO gene polymorphisms with obesity and other biochemical parameters in the Mexican population. We also assessed FTO gene expression levels in adipose tissue of obese and nonobese individuals. The study comprised 788 unrelated Mexican‐Mestizo individuals and 31 subcutaneous fat tissue biopsies from lean and obese women. FTO single‐nucleotide polymorphisms (SNPs) rs9939609, rs1421085, and rs17817449 were associated with obesity, particularly with class III obesity, under both additive and dominant models (P = 0.0000004 and 0.000008, respectively). These associations remained significant after adjusting for admixture (P = 0.000003 and 0.00009, respectively). Moreover, risk alleles showed a nominal association with lower insulin levels and homeostasis model assessment of B‐cell function (HOMA‐B), and with higher homeostasis model assessment of insulin sensitivity (HOMA‐S) only in nonobese individuals (P dom = 0.031, 0.023, and 0.049, respectively). FTO mRNA levels were significantly higher in subcutaneous fat tissue of class III obese individuals than in lean individuals (P = 0.043). Risk alleles were significantly associated with higher FTO expression in the class III obesity group (P = 0.047). In conclusion, FTO is a major risk factor for obesity (particularly class III) in the Mexican‐Mestizo population, and is upregulated in subcutaneous fat tissue of obese individuals.

Exercise Increases Serum Fibroblast Growth Factor 21 (FGF21) Levels

Background Fibroblast growth factor 21 (FGF21) increases glucose uptake. It is unknown if FGF21 serum levels are affected by exercise. Methodology/Principal Findings This was a comparative longitudinal study. Anthropometric and biochemical evaluation were carried out before and after a bout of exercise and repeated after two weeks of daily supervised exercise. The study sample was composed of 60 sedentary young healthy women. The mean age was 24±3.7 years old, and the mean BMI was 21.4±7.0 kg/m2. The anthropometric characteristics did not change after two weeks of exercise. FGF21 levels significantly increased after two weeks of exercise (276.8 ng/l (142.8–568.6) vs. (460.8 (298.2–742.1), p<0.0001)). The delta (final–basal) log of serum FGF21, adjusted for BMI, showed a significant positive correlation with basal glucose (r = 0.23, p = 0.04), mean maximal heart rate (MHR) (r = 0.54, p<0.0001), mean METs (r = 0.40, p = 0.002), delta plasma epinephrine (r = 0.53, p<0.0001) and delta plasma FFAs (r = 0.35, p = 0.006). A stepwise linear regression model showed that glucose, MHR, METs, FFAs, and epinephrine, were factors independently associated with the increment in FGF21 after the exercise program (F = 4.32; r2 = 0.64, p<0.0001). Conclusions Serum FGF21 levels significantly increased after two weeks of physical activity. This increment correlated positively with clinical parameters related to the adrenergic and lipolytic response to exercise. Trial Registration ClinicalTrials.gov NCT01512368

Prevalence of dyslipidemias in the Mexican National Health and Nutrition Survey 2006

OBJECTIVE To describe the prevalence of lipid abnormalities found in the Mexican National Health and Nutrition Survey 2006 (ENSANut 2006). MATERIAL AND METHODS Information was obtained from 4 040 subjects aged 20 to 69 years, studied after a 9- to 12-hour fast. RESULTS Median lipid concentrations were: cholesterol 198.5 mg/dl, triglycerides 139.6 mg/dl, HDL-cholesterol 39.0 mg/dl, non-HDL-cholesterol 159.5 mg/dl and LDL-cholesterol 131.5 mg/dl. The most frequent abnormality was HDL-cholesterol below 40 mg/dl with a prevalence of 60.5% (95%CI 58.2-62.8%). Hypercholesterolemia (> 200 mg/dl) had a frequency of abnormality of 43.6% (95%CI 41.4-46.0%). Only 8.6% of the hypercholesterolemic subjects knew their diagnosis. Hypertriglyceridemia (>or= 150 mg/dl) was observed in 31.5% (IC 95% 29.3-33.9%) of the population. CONCLUSIONS The ENSANUT 2006 data confirm that the prevalence of hypoalphalipoproteinemia and other forms of dyslipidemia in Mexican adults is very high.

Total and high molecular weight adiponectin have similar utility for the identification of insulin resistance.

BackgroundInsulin resistance (IR) and related metabolic disturbances are characterized by low levels of adiponectin. High molecular weight adiponectin (HMWA) is considered the active form of adiponectin and a better marker of IR than total adiponectin. The objective of this study is to compare the utility of total adiponectin, HMWA and the HMWA/total adiponectin index (SA index) for the identification of IR and related metabolic conditions.MethodsA cross-sectional analysis was performed in a group of ambulatory subjects, aged 20 to 70 years, in Mexico City. Areas under the receiver operator characteristic (ROC) curve for total, HMWA and the SA index were plotted for the identification of metabolic disturbances. Sensitivity and specificity, positive and negative predictive values, and accuracy for the identification of IR were calculated.ResultsThe study included 101 men and 168 women. The areas under the ROC curve for total and HMWA for the identification of IR (0.664 vs. 0.669, P = 0.74), obesity (0.592 vs. 0.610, P = 0.32), hypertriglyceridemia (0.661 vs. 0.671, P = 0.50) and hypoalphalipoproteinemia (0.624 vs. 0.633, P = 0.58) were similar. A total adiponectin level of 8.03 μg/ml was associated with a sensitivity of 57.6%, a specificity of 65.9%, a positive predictive value of 50.0%, a negative predictive value of 72.4%, and an accuracy of 62.7% for the diagnosis of IR. The corresponding figures for a HMWA value of 4.25 μg/dl were 59.6%, 67.1%, 51.8%, 73.7% and 64.2%.The area under the ROC curve of the SA index for the identification of IR was 0.622 [95% CI 0.554-0.691], obesity 0.613 [95% CI 0.536-0.689], hypertriglyceridemia 0.616 [95% CI 0.549-0.683], and hypoalphalipoproteinemia 0.606 [95% CI 0.535-0.677].ConclusionsTotal adiponectin, HMWA and the SA index had similar utility for the identification of IR and metabolic disturbances.

The Role of Fibroblast Growth Factor 21 (FGF21) on Energy Balance, Glucose and Lipid Metabolism

FGF21 is a novel member of the FGFs family, is mainly expressed in liver and it functions as a potent activator of glucose uptake on adipocytes. When over expressed in transgenic mice, it protects animals from diet-induced obesity and its administration to diabetic rodents and monkeys lowers blood glucose and triglyceride levels. Recently, increased levels of FGF21 have been identified as an independent risk factor related with metabolic syndrome. A review of the relevant roles of FGF21 in metabolism is presented here.

Locus on Chromosome 6p Linked to Elevated HDL Cholesterol Serum Levels and to Protection Against Premature Atherosclerosis in a Kindred With Familial Hypercholesterolemia

Abstract— Heterozygous familial hypercholesterolemia (FH) is a highly atherogenic genetic disorder leading to premature coronary heart disease (CHD), usually before 60 years of age. We studied an extended multigenerational kindred with FH linked to chromosome 1p32 in which atherosclerotic complications were either delayed or prevented in individuals with elevated HDL cholesterol (HDL-C) levels or hyperalphalipoproteinemia (HA). Premature CHD was observed in FH individuals without HA. The study of this family established that the HA trait in the family also followed an autosomal dominant mode of inheritance with a pattern of segregation independent from FH. We identified a locus on chromosome 6 linked to elevated HDL-C levels (HA) in this family. Haplotype analysis refined the localization to a 7.32-cM interval (73 to 80 cM from pter) flanked by markers D6S1280 and D6S1275. Parametric 2-point and multipoint analyses yielded maximum LOD scores of 3.05 and 3.17, respectively. This finding was confirmed with a nonparametric multipoint score of 3.78 (P =0.0009). We propose that this locus, linked to elevated HDL-C levels, confers protection against premature CHD within an FH context.

HbA1c for the Diagnosis of Diabetes Mellitus in a Developing Country. A Position Article

An Expert Committee of the American Diabetes Association and the European Association for the Study of Diabetes recommended a move to the use of HbA1c level to diagnose diabetes mellitus. Diagnosis should be made if the A1c level is > or = 6.5%. HbA1c provides a reliable measure of chronic glycemia, correlates well with the risk of long-term diabetes complications and technical limitations for standardization have been overcome in laboratories of the U.S. and Europe. The objective of this paper is to analyze critically the advantages and disadvantages of the use of HbA1c as a diagnostic method of diabetes in a developing country. The lack of a universal threshold for the diagnosis of diabetes, the cost of the test and the absence of the standardization network in the majority of the countries are major arguments for not including HbA1c as diagnostic criteria of diabetes. HbA1c diagnostic criteria has a low sensitivity. As a result, there is a lack of agreement between the HbA1c criteria with the other diagnostic methods that lead into significant variations in the number of affected cases. In addition, sensitivity and specificity vary among ethnic groups. No study has compared the diagnostic properties of the HbA1c in Latin America. In conclusion, the logistic limitations that exist in a large proportion of developing countries and the unsolved uncertainties that exist for the definition of the A1c criterion are strong arguments against the inclusion of HbA1c among the diagnostic criteria of diabetes.