The effect of leptin concentrations and other maternal characteristics on gestational weight gain is different according to pre-gestational BMI: results from a prospective cohort.

OBJECTIVE: To evaluate the effect of leptin and other selected variables on gestational weight gain (GWG) according to pre-gestational body mass index (BMI). DESIGN: Prospective cohort. SETTING: Public Health Center, Rio de Janeiro, Brazil. SAMPLE: Two hundred and twenty-eight pregnant women. METHODS: Women were followed at the 5-13, 20-26 and 30-36th gestational weeks. The effects of independent variables on GWG in normal weight (BMI 18.5-24.9 kg/m(2) ), overweight (BMI 25.0-29.9 kg/m(2) ) and obese (BMI ≥ 30.0 kg/m(2) ) women were assessed using longitudinal linear mixed-effects models. MAIN OUTCOME MEASURE: Maternal body weight (kg) throughout pregnancy. RESULTS: Leptin concentrations were associated with GWG in normal weight (ß = 0.048, P < 0.001) and overweight (ß = 0.023, P = 0.048) women, but not in obese ones (ß = 0.011, P = 0.308). Additionally, the number of hours slept per night decreased the effect of leptin on GWG in OW women (ß = -0.013, P = 0.002). The effect of other maternal characteristics on GWG was different depending on the BMI category. CONCLUSIONS: Leptin concentrations were positively associated with GWG in normal weight and overweight women, but not in obese ones. Maternal height was associated with GWG in all BMI categories, but other variables such as sleep duration, QUICKI values, HDL-c, smoking habit and marital status presented differential effects according to BMI. We encourage further studies to investigate the association between leptin and gestational weight gain, taking into account the pre-pregnancy weight and sleep duration, in order to compare and confirm our results. TWEETABLE ABSTRACT: Leptin is associated with weight gain in normal weight and overweight pregnant women, but not in obese ones.

Lipid changes throughout pregnancy according to pre-pregnancy BMI: results from a prospective cohort.

OBJECTIVE: To evaluate the rate of change in serum lipids and the factors associated with their variations, stratifying for pre-pregnancy body mass index (BMI) categories. DESIGN: Prospective cohort. SETTING: Public Health centre, Rio de Janeiro, Brazil. POPULATION: Two hundred and twenty-five healthy pregnant women recruited between 2009 and 2011. METHODS: Women were evaluated during the three trimesters of pregnancy (5th-13th, 20th-26th and 30th-36th gestational weeks). Pre-pregnancy BMI (kg/m²) was classified as normal weight (NW = 18.5-24.9), overweight (OW = 25.0-29.9) or obese (OB ≥ 30.0). The independent variables included maternal socioeconomic, demographic, biochemical and lifestyle factors. We performed linear mixed-effects models adjusted for gestational age and body weight, reporting coefficient (ß) and 95% confidence interval (95% CI). MAIN OUTCOME MEASURES: Longitudinal total cholesterol (TC), high-density lipoprotein (HDL-c), low-density lipoprotein (LDL-c) and triglyceride (TG) measurements. RESULTS: OW and OB women presented higher mean TG, TC and LDL-c compared with their NW counterparts (P < 0.05). The mean HDL-c concentrations were higher in NW than in OB women (P = 0.03). OW and OB women presented lower serum TC (ßOW  = -0.014; 95% CI = -0.026 to -0.002; P = 0.022; ßOB  = -0.015; 95% CI -0.015 to 0.001; P = 0.066) and LDL-c (ßOW  = -0.012; 95% CI = -0.021 to -0.002; P = 0.017; ßOB  = -0.018; 95% CI = -0.031 to -0.005; P = 0.005) rates of change (mmol/l per gestational week) compared with the NW. Pre-gestational BMI was the main factor associated with the rate of changes in TC and LDL-c concentrations. CONCLUSION: Pre-pregnancy BMI was the main factor associated with the rate of change in TC and LDL-c throughout pregnancy, and OW and OB women presented lower rates of change compared with NW controls.

Moderate hyperhomocysteinemia provokes dysfunction of cardiovascular autonomic system and liver oxidative stress in rats.

Hyperhomocysteinemia (HHcy) is associated with cardiovascular disease, atherosclerosis and reactive oxygen species generation. Thus, our aim was to investigate whether there was an association between HHcy, blood pressure, autonomic control and liver oxidative stress. Male Wistar rats were divided into 2 groups and treated for 8weeks: one group (control, CO) received tap water, while the other group (methionine, ME) was given a 100mg/kg of methionine in water by gavage. Two catheters were implanted into the femoral artery and vein to record arterial pressure (AP) and heart rate (HR) and drug administration. Signals were recorded by a data acquisition system. Baroreflex sensitivity was evaluated by HR responses to AP changes induced by vasoactive drugs. HR variability and AP variability were performed by spectral analysis in time and frequency domains to evaluate the contribution of the sympathetic and parasympathetic modulation. Lipid peroxidation and antioxidant enzyme activities were evaluated by measuring superoxide dismutase, catalase and glutathione peroxidase in liver homogenates. The ME group presented a significant increase in systolic arterial pressure (118±9 vs 135±6mmHg), diastolic arterial pressure (81±6 vs. 92±4) and mean arterial pressure (95±7 vs. 106±6). In addition, pulse interval variability presented a significant decrease (41%), while the low frequency component of AP was significantly increased (delta P=6.24mmHg(2)) in the ME group. We also found a positive association between lipid peroxidation and cardiac sympathetic modulation, sympathetic and vagal modulation ratio and systolic pressure variability. Collectively, these findings showed that HHcy induced dysfunction of cardiovascular autonomic system and liver oxidative stress.

Homocysteine thiolactone induces cardiac dysfunction: role of oxidative stress.

This study investigates the cardiac functioning in male Wistar rats after treatments with methionine and homocysteine thiolactone (HcyT). The rats were distributed into 3 groups and treated for 8 weeks. Group I was the control (CO) group, given water, group II was treated with methionine, and group III with HcyT (100 mg/kg). Morphometric and functional cardiac parameters were evaluated by echocardiography. Superoxide dismutase (SOD), catalase, and glutathione S-transferase activities, chemiluminescence, thiobarbituric acid reactive substances, and immunocontent were measured in the myocardium. Hyperhomocysteinemiawas observed in rats submitted to the both treatments. The results showed diastolic function was compromised in HcyT group, seen by the increase of E/A (peak velocity of early (E) and late (A) diastolic filling) ratio, decrease in deceleration time of E wave and left ventricular isovolumic relaxation time. Myocardial performance index was increased in HcyT group and was found associated with increased SOD immunocontent. HcyT group demonstrated an increase in SOD, catalase, and glutatione S-transferase activity, and chemiluminescence and thiobarbituric acid reactive substances. Overall, these results indicated that HcyT induces a cardiac dysfunction and could be associated with oxidative stress increase in the myocardium.