Ana Petelin

Serum bilirubin levels are lower in overweight asymptomatic middle-aged adults: An early indicator of metabolic syndrome?

OBJECTIVE Low levels of bilirubin have recently been associated with obesity, diabetes mellitus, and metabolic syndrome. Here, we hypothesized that serum bilirubin levels might be already altered in overweight asymptomatic middle-aged individuals before full development of the metabolic syndrome. METHODS Healthy nonsmoking adults aged 25-49 (64 women and 32 men) participated in this cross-sectional study. All participants who reported stable weight within the last three months underwent standard anthropomorphological measurements of body composition, blood pressure measurements, aerobic and anaerobic capabilities assessment, dietary intake evaluation, and fasting serological measurements of total and direct bilirubin, glucose, insulin, triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and C-reactive protein. Participants were divided into normal-weight and overweight groups. Linear correlation and multiple regression analyses were used to examine the association of serum bilirubin levels with all metabolic syndrome risk factor changes. RESULTS Serum bilirubin levels were lower in overweight healthy individuals of both sexes, and were negatively associated with abdominal obesity, insulin resistance, fasting glucose, fasting insulin, fasting triglycerides, total cholesterol, low-density lipoprotein cholesterol, and C-reactive protein levels but positively associated with aerobic body capabilities. CONCLUSION Our findings suggest that serum bilirubin levels have the potential to be employed as an early biomarker for indicating asymptomatic individuals at increased risk of developing metabolic syndrome.

Inverse relationship between "a body shape index" (ABSI) and fat-free mass in women and men: Insights into mechanisms of sarcopenic obesity.

BACKGROUND & AIMS Sarcopenic obesity may be defined by a high fat to fat-free mass (FM/FFM) ratio. Skeletal muscle may be negatively influenced by the pro-inflammatory milieu associated with visceral fat, while the loading effect induced by a heavier body mass index (BMI) may enhance muscle anabolism. Recently, a new anthropometric measure based on waist circumference (A Body Shape Index, ABSI) was developed. In this study we have assessed the predictive power of ABSI on the FFM index (FFMI), a surrogate marker of lean mass. METHODS Standard anthropometric parameters and ABSI as well as body composition data (fat and fat-free mass determined by bioelectrical impedance analysis) were assessed in 111 female and 89 male overweight/obese subjects, with no clinically significant co-morbidities. Groups with higher- or lower-ABSI were identified according to median values of this index. RESULTS In women and men, ABSI did not correlate with BMI, while multiple linear regression indicated that BMI (β-coefficients: 0.62 and 0.77, respectively) and ABSI (β-coefficients: -0.26 and -0.22, respectively) independently predicted FFMI (multiple R: 0.72 and 0.83, respectively, P < 0.001). Men and women with lower-ABSI exhibited significantly greater FFMI than the higher-ABSI groups for comparable values of BMI. In men, ABSI was correlated positively with C-reactive protein (CRP) (R = 0.30; P < 0.05) and negatively with the reciprocal of insulin (R = 0.28; P < 0.05), an index of insulin sensitivity. FM/FFM ratio significantly (P < 0.01) correlated with CRP (R = 0.31) in women only. CONCLUSIONS ABSI, a recently introduced marker of abdominal adiposity, may contribute to define the risk of sarcopenia in overweight/obese individuals.

Elevated Serum Levels of Cysteine and Tyrosine: Early Biomarkers in Asymptomatic Adults at Increased Risk of Developing Metabolic Syndrome

As there is effective intervention for delaying or preventing metabolic diseases, which are often present for years before becoming clinically apparent, novel biomarkers that would mark metabolic complications before the onset of metabolic disease should be identified. We investigated the role of fasting serum amino acids and their associations with inflammatory markers, adipokines, and metabolic syndrome (MetS) components in subjects prior to the onset of insulin resistance (IR). Anthropometric measurements, food records, adipokines, biochemical markers, and serum levels of amino acids were determined in 96 asymptomatic subjects aged 25–49 years divided into three groups according to the number of MetS components present. Cysteine and tyrosine were significantly higher already in group with one component of MetS present compared to subjects without MetS components. Serum amino acid levels correlated with markers of inflammation and adipokines. Alanine and glycine explained 10% of insulin resistance variability. The role of tyrosine and cysteine, that were higher already with 1 component of MetS present, should be further investigated as they might point to future insulin disturbances.

Total Serum Antioxidant Capacity in Healthy Normal Weight and Asymptomatic Overweight Adults

Obesity and overweight are major contributors to the burden of chronic disease. Both are defined as abnormal or excessive fat accumulation and by increased production of free radicals leading to oxidative stress. The aim of the present study was to evaluate whether overweight and fat accumulation is associated with serum total antioxidant capacity (TAC) in men and women, irrespective of nutritional habits, nutrient intakes, physical activity, smoking, and other confounders, which may be responsible for modifying the association between serum TAC and overweight/obesity measures. This cross-sectional study was conducted on 60 normal weight and 60 overweight adults aged 25-49. All participants underwent standard anthromorphological measurements of body composition, blood pressure and biochemical measurements, aerobic capabilities assessment and dietary intake evaluation. TAC was measured by using the photochemioluminescence method. All data were analysed with SPSS software. Men had higher values of TAC than women and concentrations of TAC were significantly higher in overweight subjects compared to normal weight subjects. In the present study TAC tended to be increased by various metabolic risk factors, especially overweight/obesity parameters (body mass index, body fat), inflammation and increased serum levels of Cysteine, irrespective of nutritional habits, nutrient intakes, physical activity and smoking. Overweight and obesity at an early stage may stimulate TAC. Therefore, the elevation of TAC in overweight adults may be a compensatory response to oxidative stress, generated by reactive oxygen species.

Increased Risk-Taking Behaviour and Brain-Derived Neurotrophic Factor Val66Met Polymorphism Correlates to Decreased Serum Brain-Derived Neurotrophic Factor Level in Heroin Users

Background: This study has examined the relationships and interactions between serum brain-derived neurotrophic factor (BDNF) levels, BDNF Val66Met polymorphism and self-reported risk-taking behaviour in individuals with a history of heroin use undergoing outpatient treatment in comparison to healthy individuals. Methods: We enrolled 167 heroin users and 86 healthy subjects and examined serum BDNF levels, Val66Met polymorphism, and personal characteristics using Connor Davidson Resilience Scale, Risk-taking (RT) propensity questionnaire, and Personality Assessment Inventory. Results: Heroin users had significantly higher serum BDNF levels than controls. In addition, serum BDNF levels were significantly higher in Val/Val carriers than in Met/Val or Met/Met in all recruited subjects. Furthermore, a stepwise multiple regression analysis of serum BDNF levels as a dependent variable with related factors showed that in heroin users, Alcohol Use Disorder Identification Test score, anxiety and RT score were found as independent contributors to serum BDNF levels. When performing gene-environment interaction it was additionally found that heroin users with self-reported high risk-taking behaviour had significantly lower levels of serum BDNF among heroin users with the Met allele. Conclusions: These results indicate that genetic variant Met66 decreased the serum BDNF levels in combination with self-reported risk-taking propensity among heroin users. If results of future work confirm the influence of this combined effect between neurotrophic genotype and risk-taking behaviour, 66Met carriers might require higher levels of intervention to overcome their drug use pattern and risky behaviour.