[Metabolic syndrome, its phenotypes, and insulin resistance by HOMA-IR]

Relationship between Leptin and Insulin Resistance among Community-Dwelling Middle-Aged and Elderly Populations in Taiwan

The relationship between leptin and insulin resistance among middle-aged and elderly populations in Asia is seldom reported. Our research included 398 middle-aged and elderly Taiwanese individuals. First, we divided participants into three groups according to the tertiles of the homeostasis model assessment of insulin resistance (HOMA-IR) to analyze the parameters between each group. Pearson’s correlation was then applied to calculate the correlation between HOMA-IR and cardiometabolic risk factors after adjusting for age. A scatter plot indicated a relationship between serum leptin levels and the HOMA-IR index. Finally, the coefficients of the serum leptin level and HOMA-IR were assessed by multivariate linear regression. The participants in the high HOMA-IR index group were more likely to have higher serum leptin levels. Meanwhile, the HOMA-IR index was positively correlated with serum leptin levels, even after adjusting for age. Serum leptin levels were positively correlated with the HOMA-IR index (β = 0.226, p < 0.01) in the multivariate linear regression after adjusting for age, sex, smoking, drinking, BMI, triglycerides, systolic blood pressure, fasting plasma glucose, uric acid, ALT, and creatinine. Furthermore, the leptin−creatinine ratio also showed a significantly positive relationship with HOMA-IR in the same multivariate linear regression model. In conclusion, serum leptin levels showed a positive relationship with insulin resistance in middle-aged and elderly people in Taiwan. Furthermore, serum leptin levels may be an independent risk factor for insulin resistance according to our study.

CURING HEPATITIS C WITH THE NEW DIRECT ACTING ANTIVIRALS DID NOT IMPROVE INSULIN RESISTANCE AFTER ONE YEAR

BACKGROUND

Chronic hepatitis C still figures as an important cause of morbidity among the Brazilian population, and is closely associated with metabolic disturbances, including insulin resistance (IR), which can be evaluated by the Homeostatic Model Assessment (HOMA-IR). IR may entail lower sustained virologic response (SVR) on certain therapeutic regimens and faster progression to advanced hepatic fibrosis. With the arrival of the direct acting agents (DAA) in hepatitis C treatment, there is an increased need in observing the impact in patients' IR profile while using such therapies.

OBJECTIVE

- 1) To compare the results of HOMA-IR in patients affected by chronic hepatitis C before treatment with DAA and 12 months after finishing it with SVR. 2) To evaluate the evolution of weight after curing chronic hepatitis C.

METHODS

We included patients older than 18 from two tertiary care in Curitiba - PR, of both sexes, with chronic hepatitis C, treated with DAA, from July 2015 to September 2017. We also evaluated the patients' levels of fasting insulin, fasting glucose and glycated hemoglobin before starting treatment and 12 months after finishing it. We also used epidemiologic data, such as age, sex, hepatic fibrosis degree, body mass index, abdominal circumference, viral genotype and the presence of diabetes mellitus before and after treatment. IR was assessed before and after treatment and calculated by the HOMA-IR score. Insulin resistance was defined by a HOMA-IR greater than 2.5. We excluded patients who lost follow-up, those who did not achieve SRV and those who did not have a laboratory profile. The results of quantitative variables were described by means, medians, and standard deviations. P values <0.05 indicated statistical significance.

RESULTS

We included 75 patients in this study, with a mean age of 55.2 years and 60% of males. Forty-three patients had advanced fibrosis. Twenty one (28%) had a previous diabetes mellitus diagnosis. We identified 31 (41.3%) patients with IR before antiviral treatment, and this number increased to 39 (52%) after 12 months of finishing treatment, according to HOMA-IR. There was no statistic difference between insulin, glucose and HOMA-IR measurements before and after curing hepatitis C. We observed a weight gain in patients shortly after curing hepatitis C, but this did not persist at the end of the study. We also had no significant difference in IR prevalence when viral genotype was concerned.

CONCLUSION

In this study, there was no statistically significant difference between HOMA-IR results in patients before and 12 months after treatment for hepatitis C. Even though patients gained weight after the cure, this was not statistically significant after a year (P=0.131).

Tamarind Trypsin Inhibitor in Chitosan-Whey Protein Nanoparticles Reduces Fasting Blood Glucose Levels without Compromising Insulinemia: A Preclinical Study

In vivo studies show the benefits of the trypsin inhibitor isolated from tamarind (Tamarindusindica L.) (TTI) seeds in satiety and obesity. In the present study, TTI nanoencapsulation (ECW) was performed to potentialize the effect of TTI and allow a controlled release in the stomach. The impact on glycemia, insulin, and lipid profile was evaluated in Wistar rats overfed with a high glycemic index diet (HGLI). Characterization of the nanoparticles and in vitro stability in simulated gastrointestinal conditions, monitored by antitrypsin activity and HPLC, was performed. ECW and empty nanoparticles (CW) were administered by gavage, using 12.5 and 10.0 mg/kg, respectively. Both nanoformulations presented a spherical shape and smooth surface, with an average diameter of 117.4 nm (24.1) for ECW and 123.9 nm (11.3) for CW. ECW maintained the antitrypsin activity (95.5%) in the gastric phase, while TTI was completely hydrolyzed. In Wistar rats, the nanoformulations significantly reduced glycemia and HOMA IR, and ECW increased HDL-c compared to CW (p < 0.05).Pancreas histopathology of animals treated with ECW suggested an onset of tissue repair. Thenanoencapsulation provided TTI protection, gradual release in the desired condition, and improvement of biochemical parameters related to carbohydrate metabolism disorders,without compromising insulinemia.

The Prevalence of Metabolic Syndrome in the Different Phenotypes of Polycystic Ovarian Syndrome

OBJECTIVE

 To evaluate the prevalence of metabolic syndrome (MetS) in the phenotypes of polycystic ovarian syndrome (PCOS).

METHODS

 This was a cross-sectional study involving 111 women aged between 18 and 39 years old diagnosed with PCOS, according to the Rotterdam Criteria, and grouped into four phenotypes: A: ovulatory dysfunction + hyperandrogenism + polycystic ovaries; B: ovulatory dysfunction + hyperandrogenism; C: hyperandrogenism + polycystic ovaries; D: ovulatory dysfunction + polycystic ovaries. To evaluate the presence of MetS, we measured serum triglyceride levels, HDL cholesterol, fasting blood glucose, blood pressure, and waist circumference.

RESULTS

 The prevalence of MetS found in this sample was 33.6%, and there was no statistically significant difference (p < 0.05) among the 4 phenotypes. However, phenotype D presented a significantly higher mean glucose level after fasting (93.6 mg/dL) and 2 hours after ingesting a solution with 75 g of anhydrous glucose (120 mg/dL), as well as the lowest mean level of high-density lipoprotein (HDL) cholesterol (44.7 mg/dL). The women in this group demonstrated a high prevalence of abdominal circumference ≥ 80 cm (68.2%), as well as the highest mean abdominal circumference (90.1 cm). Amongst the women with an abdominal circumference ≥ 80 cm, phenotype A increased approximately six-fold the chance of developing metabolic syndrome in relation to phenotype C.

CONCLUSION

 The four phenotypes of PCOS demonstrated similar prevalence rates of metabolic syndrome; abdominal obesity presented a relevant role in the development of metabolic alterations, regardless of the phenotype.

Metabolic syndrome components are associated with oxidative stress in overweight and obese patients

OBJECTIVE

The aim of this study is to evaluate the influence of the body mass index (BMI) and the metabolic syndrome (MetS) parameters on oxidative and nitrosative stress in overweight and obese subjects.

SUBJECTS AND METHODS

Individuals were divided into three groups: the control group (G1, n = 131) with a BMI between 20 and 24.9 kg/m2, the overweight group (G2, n = 120) with a BMI between 25 and 29.9 kg/m2 and the obese group (G3, n = 79) with a BMI ≥ 30 kg/m2.

RESULTS

G3 presented higher advanced oxidation protein products (AOPPs) in relation to G1 and G2 (p = 0.001 and p = 0.011, respectively) whereas G2 and G3 had lower levels of nitric oxide (NO) (p = 0.009 and p = 0.048, respectively) compared to G1. Adjusted for the presence of MetS to evaluate its influence, the levels of AOPPs did not differ between the groups, whereas NO remained significantly lower. Data adjusted by the BMI showed that subjects with higher triacylglycerol levels had higher AOPPs (p = 0.001) and decreased total radical-trapping antioxidant parameter/uric Acid (p = 0.036). Subjects with lower high-density lipoprotein (HDL) levels and patients with higher blood pressure showed increased AOPPs (p = 0.001 and p = 0.034, respectively) and lower NO levels (p = 0.017 and p = 0.043, respectively). Subjects who presented insulin resistance had higher AOPPs (p = 0.024).

CONCLUSIONS

Nitrosative stress was related to BMI, and protein oxidation and nitrosative stress were related to metabolic changes and hypertension. MetS components were essential participants in oxidative and nitrosative stress in overweight and obese subjects.

The 482Ser of PPARGC1A and 12Pro of PPARG2 Alleles Are Associated with Reduction of Metabolic Risk Factors Even Obesity in a Mexican-Mestizo Population

The aim of this study was to investigate the relationship between functional polymorphisms Gly482Ser in PPARGC1A and Pro12Ala in PPARG2 with the presence of obesity and metabolic risk factors. We included 375 individuals characterized as Mexican-Mestizos and classified by the body mass index (BMI). Body dimensions and distribution of body fat were measured. The HOMA-IR and adiposity indexes were calculated. Adipokines and metabolic profile quantification were performed by ELISA and routine methods. Genetic polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphism analysis. A difference between obese and nonobese subjects in polymorphism PPARGC1A distribution was observed. Among obese individuals, carriers of genotype 482Gly/Gly were observed to have decreased body fat, BMI, and body fat ratio versus 482Ser/Ser carriers and increased resistin and leptin levels in carriers Gly+ phenotype versus Gly- phenotype. Subjects with PPARG2 Ala- phenotype (genotype 12Pro/Pro) showed a decreased HOMA-IR index versus individuals with Ala+ phenotype (genotypes 12Pro/Ala plus 12Ala/Ala). We propose that, in obese Mexican-Mestizos, the combination of alleles 482Ser in PPARGC1A and 12Pro in PPARG2 represents a reduced metabolic risk profile, even when the adiposity indexes are increased.

Sleepiness, inflammation and oxidative stress markers in middle-aged males with obstructive sleep apnea without metabolic syndrome: a cross-sectional study

BACKGROUND

The simultaneous occurrence of metabolic syndrome and excessive daytime sleepiness are very common in obstructive sleep apnea (OSA) patients. Both conditions, if present in OSA, have been reported to be associated with inflammation and disruption of oxidative stress balance that impair the cardiovascular system. To verify the impact of daytime sleepiness on inflammatory and oxidative stress markers, we evaluated OSA patients without significant metabolic disturbance.

METHODS

Thirty-five male subjects without diagnostic criteria for metabolic syndrome (Adult Treatment Panel III) were distributed into a control group (n = 10) (43 ± 10.56 years, apnea-hypopnea index - AHI 2.71 ± 1.48/hour), a non-sleepy OSA group (n = 11) (42.36 ± 9.48 years, AHI 29.48 ± 22.83/hour) and a sleepy OSA group (n = 14) (45.43 ± 10.06 years, AHI 38.20 ± 25.54/hour). Excessive daytime sleepiness was considered when Epworth sleepiness scale score was ≥ 10. Levels of high-sensitivity C-reactive protein, homocysteine and cysteine, and paraoxonase-1 activity and arylesterase activity of paraoxonase-1 were evaluated.

RESULTS

Patients with OSA and excessive daytime sleepiness presented increased high-sensitivity C-reactive protein levels even after controlling for confounders. No significant differences were found among the groups in paraoxonase-1 activity nor arylesterase activity of paraoxonase-1. AHI was independently associated and excessive daytime sleepiness tended to have an association with high-sensitivity C-reactive protein.

CONCLUSIONS

In the absence of metabolic syndrome, increased inflammatory response was associated with AHI and daytime sleepiness, while OSA was not associated with abnormalities in oxidative stress markers.

Menstrual irregularity: a possible clinical marker of metabolic dysfunction in women with class III obesity

PURPOSE

To evaluate whether menstrual irregularity in morbidly obese women is indicative of metabolic dysfunction.

PATIENTS AND METHODS

Fifty-seven women with morbid obesity were evaluated. They were divided into two groups: one comprising women without menstrual dysfunctions or hirsutism (Group 1), and another obese women showing menstrual dysfunction with or without hirsutism (Group 2). The following were evaluated: age, colour, childbirth, marital status, profession, socio-economic level, education, age at menarche, body weight, height, body mass index, presence of hirsutism (Ferriman Gallwey Index), abdominal circumference, hip circumference, waist-to-hip ratio, menstrual cycle, blood pressure, presence of acanthosis nigricans, insulin resistance (IR), fasting glycaemia, total cholesterol, HDL-C, LDL-C, triglycerides, thyroid-stimulating hormone, free T4, luteinising hormone (LH), follicle-stimulating hormone, prolactin, total testosterone, dehydroepiandrosterone sulfate, insulin and the Homeostasis Model Assessment (HOMA test).

RESULTS

Clinical and epidemiological aspects did not present statistical differences. Clinical and laboratory parameters did not show statistically significant alterations; however, HOMA test values for Group 2 were significantly higher than those for Group 1.

CONCLUSIONS

The presence of IR in class III obese women can cause menstrual dysfunctions such as amenorrhoea or oligomenorrhoea even in the absence of hyperandrogenism, suggesting that IR plays an important role in the ovarian mechanisms involved in the menstrual cycle control.