Heriberto Rodríguez-Hernández

Obesity and inflammation: epidemiology, risk factors, and markers of inflammation.

Obesity is a public health problem that has reached epidemic proportions with an increasing worldwide prevalence. The global emergence of obesity increases the risk of developing chronic metabolic disorders. Thus, it is an economic issue that increased the costs of the comorbidities associated. Moreover, in recent years, it has been demonstrated that obesity is associated with chronic systemic inflammation, this status is conditioned by the innate immune system activation in adipose tissue that promotes an increase in the production and release of pro-inflammatory cytokines that contribute to the triggering of the systemic acute-phase response which is characterized by elevation of acute-phase protein levels. On this regard, low-grade chronic inflammation is a characteristic of various chronic diseases such as metabolic syndrome, cardiovascular disease, diabetes, hypertension, non-alcoholic fatty liver disease, and some cancers, among others, which are also characterized by obesity condition. Thus, a growing body of evidence supports the important role that is played by the inflammatory response in obesity condition and the pathogenesis of chronic diseases related.

Adding cognitive behavioural treatment to either low-carbohydrate or low-fat diets: differential short-term effects.

To evaluate the efficacy of adding cognitive behavioural treatment (CBT) to either a low-carbohydrate (LC) diet or a low-fat (LF) diet in the treatment of weight loss of obese women, a randomised clinical intervention study was performed. A total of 105 healthy non-pregnant obese women (average age and BMI of 45.4 (sd 10.4) years and 36 (sd 4.3) kg/m2) were randomly allocated to the CBT or control (C) groups; within each group, women were randomly selected to receive either the LC or LF diet during 6 months. The pre-planned primary trial end-point was the weight loss. Differences between the groups were assessed using one-way ANOVA. There were three women (2.8 %) who dropped out, all of them in the CBT group. No differences in the anthropometric and laboratory characteristics at baseline were noted between women in the CBT (n 52) and control groups (n 50). Intention-to-treat analysis showed that weight loss in the CBT-LC (90 (sd 12.3) to 82.1 (sd 12.1) kg) and C-LC (89.4 (sd 10.0) to 85.8 (sd 9.8) kg) groups reached 8.7 and 4.0 %, respectively (P < 0.0001), and in the CBT-LF (87.9 (sd 11.4) to 79.4 (sd 11.8) kg) and C-LF (88.8 (sd 14.5) to 85.3 (sd 14.3) kg) groups it was 9.7 and 3.9 %, respectively (P < 0.05). Weight loss was higher in the CBT-LF group than in the CBT-LC groups (P = 0.049). The present results showed that adding CBT to either the LF or LC diet produced significantly greater short-term weight loss in obese women compared with diet alone. These finding support the efficacy of CBT in breaking previous dietary patterns and in developing healthier attitudes that reinforce a healthier lifestyle.

Risk factors associated with nonalcoholic fatty liver disease and its relationship with the hepatic histological changes.

Objective The objective of this study is to determine the association between risk factors and nonalcoholic fatty liver disease (NAFLD), and to establish the relationship between risk factors and hepatic histological changes in obese women. Methods A case-control design study. Women with NAFLD (cases) were compared with a control group of obese women without NAFLD matched by age, body mass index, waist circumference, and body fat. Irrespective of serum aminotransferases levels, diagnosis of NAFLD was established by the presence of type II diabetes, hypertriglyceridemia, and ultrasonographic changes of hepatic steatosis. Diagnosis of nonalcoholic steatohepatitis was performed by a liver biopsy. Women with an aspartate aminotransferase/alanine aminotransferase (ALT) ratio of at least 1 underwent liver biopsy. Alcohol consumption, hepatitis, and drugs that promote cholestasis or liver injury were the exclusion criteria. Multiple regression analysis was used to compute the association between the risk factors and NAFLD, and Spearmans analysis was used to examine its relationship with histological hepatic changes. Results A total of 108 obese women were enrolled. The frequency of high blood pressure, hypertriglyceridemia, and diabetes was similar between the groups. ALT (54.4±33.3 and 39.8±29.8, P=0.03) but not aspartate aminotransferase (45.4±23.1 and 36.7±21.2, P=0.06) was significantly higher in the women with NAFLD. The multivariate regression analysis showed a significant association of ALT (odds ratio 2.7; 95% confidence interval, 1.3–10.4), but not other variables with NAFLD. Type II diabetes was strongly correlated with ballooning and inflammation, and ALT with inflammation and fibrosis. Conclusion Obese women with similar metabolic alterations exhibit different hepatic outcomes. Elevation of ALT, but not other risk factors, was associated with NAFLD. Diabetes and ALT correlate with histological hepatic changes.

Oral magnesium supplementation decreases alanine aminotransferase levels in obese women.

To evaluate the effect of oral supplementation with magnesium chloride on the systemic and hepatic inflammation, 38 non-hypertensive obese women aged 30 to 65 years were allocated into groups with and without hypomagnesemia. Hypomagnesemic women drank 50 mL of 5% solution of MgCl2 equivalent to 450 mg of elemental magnesium. Low-carbohydrate diets and physical activity were indicated for women in both groups. Chronic diarrhea, alcohol intake, use of diuretics, previous oral magnesium supplementation, hepatic disease, and renal damage were exclusion criteria. Hypomagnesemia is defined by serum magnesium concentrations<or=1.8 mg/dL, hepatic inflammation by serum alanine aminotransferase (ALT) levels>or=40 U/L, and systemic inflammation by serum high-sensitivity C reactive protein (hs-CRP) concentration>or=3 mg/L. At baseline (p=0.06) and final of follow-up (p=0.80), there were no significant differences by body mass index between the groups in the study. In the same way, at baseline ALT (48.1+/-25.5 and 34.6+/-24.1 U/L, p=0.14) and hs-CRP (9.4+/-6.0 and 7.9+/-5.9 mg/dL, p=0.47) levels were similar in the supplemented and non-supplemented women. In the magnesium group, ALT (24.3+/-10.3 and 34.8+/-13.6 U/L, p=0.02) levels, but not hs-CRP (5.2+/-1.9 and 8.0+/-5.6 mg/L, p=0.08) reached significantly lower levels, in the fourth month of treatment, than in women in the control group. The adjusted odds ratios between the improvement in serum magnesium and reduction in ALT and hs-CRP levels were 0.56 (95% CI: 0.3-0.9) and 0.93 (95% CI: 0.6-29.9), respectively. Results of this study show that in hypomagnesemic obese women, oral supplementation with magnesium chloride reduces plasma ALT levels; hs-CRP levels only show a reduction trend.

The alanine aminotransferase to triglycerides ratio as a marker to identify nonalcoholic fatty liver disease.

Objective The aim of this study was to determine whether the alanine aminotransferase to triglycerides (ALT/TGL) ratio is useful to identify nonalcoholic fatty liver disease (NAFLD) in asymptomatic overweight and obese women. Methods Asymptomatic overweight and obese women aged 20–65 years were enrolled in a cross-sectional study for evaluating their ALT/TGL ratio, which was considered as a diagnostic test for identifying NAFLD. Alcohol consumption of at least 20 g/week, smoking, positive markers of viral or autoimmune hepatitis, a previous diagnosis of acute or chronic liver disease, renal failure, glomerulopathies, neoplasia, cardiovascular disease, and intake of contraceptives or hepatotoxic drugs were the exclusion criteria. The sensitivity, specificity, and predictive values were calculated. The optimal ALT/TGL ratio to identify NAFLD was determined using a receiver operating characteristic scatter plot analysis. Results A total of 412 asymptomatic women, average age of 45.1±10.5 years, were enrolled, 199 (48.3%) without NAFLD and 213 (51.7%) with NAFLD. The best cut-off point of the ALT/TGL ratio to identify NAFLD was 7.0, which showed the highest sensitivity (84.0%) and specificity (91.0%). For this cut-off point, the positive and negative predictive values were 91.8 and 84.3%, respectively. The weighted &kgr; test showed a good agreement between the ALT/TGL ratio and the hepatic ultrasound in the identification of NAFLD (&kgr;=0.758). Conclusion The results of this study indicate that the ALT/TGL ratio has a high sensitivity and specificity to identify NAFLD, suggesting that it could be a useful marker to recognize NAFLD in asymptomatic overweight and obese women.

The product of triglycerides and glucose as biomarker for screening simple steatosis and NASH in asymptomatic women.

INTRODUCTION AND AIM Given that early identification of non-alcoholic fatty liver disease (NAFLD) is an important issue for primary prevention of hepatic disease, the objectives of this study were to evaluate the efficacy of the product of triglyceride and glucose levels (TyG) for screening simple steatosis and non-alcoholic steatohepatitis (NASH) in asymptomatic women, and to compare its efficacy vs. other biomarkers for recognizing NAFLD. MATERIAL AND METHODS Asymptomatic women aged 20 to 65 years were enrolled into a cross-sectional study. The optimal values of TyG, for screening simple steatosis and NASH were established on a Receiver Operating Characteristic scatter plot; the sensitivity, specificity, and likelihood ratios of TyG index were estimated versus liver biopsy. According sensitivity and specificity, the efficacy of TyG was compared versus the well-known clinical biomarkers for recognizing NAFLD. RESULTS A total of 50 asymptomatic women were enrolled. The best cutoff point of TyG for screening simple steatosis was 4.58 (sensitivity 0.94, specificity 0.69); in addition, the best cutoff point of TyG index for screening NASH was 4.59 (sensitivity 0.87, specificity 0.69). The positive and negative likelihood ratios were 3.03 and 0.08 for simple steatosis, and 2.80 and 0.18 for NASH. As compared versus SteatoTest, NashTest, Fatty liver index, and Algorithm, the TyG showed to be the best test for screening. CONCLUSIONS TyG has high sensitivity and low negative likelihood ratio; as compared with other clinical biomarkers, the TyG showed to be the best test for screening simple steatosis and NASH.

Insulin resistance is associated with elevated transaminases and low aspartate aminotransferase/alanine aminotransferase ratio in young adults with normal weight.

Objective The aim of this study is to determine whether insulin resistance is associated with elevation of transaminases levels and aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio in normal-weight healthy young adults. Participants and methods Apparently healthy nonpregnant women and men, aged 18–23 years, were enrolled in a cross-sectional study. According to the homeostasis model assessment of insulin resistance, the participants were allocated into groups of patients with (>2.5) and without (⩽2.5) insulin resistance. Normal weight was defined by BMI of at least 18.5 and less than 25.0 kg/m2. A multiple logistic regression analysis was carried out to determine the association between insulin resistance and elevated transaminases and AST/ALT ratio of 1 or less. Results A total of 1732 young adults were enrolled and allocated into groups with (n=287) and without (n=1445) insulin resistance. The prevalence of insulin resistance was 16.6% in the overall population. The multivariate logistic regression analysis adjusted by age, sex, waist circumference, and BMI indicated that the odds ratio (OR) between insulin resistance and elevated ALT concentrations is 1.65 [95% confidence interval (CI): 1.04–2.62, P=0.03], for AST/ALT ratio lower than 1 OR is 1.69 (95% CI: 1.27–2.26, P<0.001), and for elevated AST levels OR is 1.31 (95% CI: 0.71–2.43, P=0.377). Conclusion The results of the present study suggest that insulin resistance is significantly associated with elevated ALT levels and AST/ALT ratio of lower than 1, but not with elevated AST levels.