Pre- and post- prandial appetite hormone levels in normal weight and severely obese women

Background

Appetite is affected by many factors including the hormones leptin, ghrelin and adiponectin. Ghrelin stimulates hunger, leptin promotes satiety, and adiponectin affects insulin response. This study was designed to test whether the pre- and postprandial response of key appetite hormones differs in normal weight (NW) and severely obese (SO) women.

Methods

Twenty three women ages 25–50 were recruited for this study including 10 NW (BMI = 23.1 ± 1.3 kg/m²) and 13 SO (BMI = 44.5 ± 7.1 kg/m²). The study was conducted in a hospital-based clinical research centre. Following a 12-hour fast, participants had a baseline blood draw, consumed a moderately high carbohydrate meal (60% carbohydrate, 20% protein, 20% fat) based on body weight. Postprandially, participants had six blood samples drawn at 0, 15, 30, 60, 90, and 120 minutes. Primary measures included pre- and post-prandial total ghrelin, leptin, adiponectin and insulin. A repeated measures general linear model was used to evaluate the hormone changes by group and time (significance p ≤ 0.05).

Results

There were significant differences between the NW and the SO for all hormones in the preprandial fasting state. The postprandial responses between the SO versus NW revealed: higher leptin (p < 0.0001), lower adiponectin (p = 0.04), trend for lower ghrelin (p = 0.06) and insulin was not different (p = 0.26). Postprandial responses over time between the SO versus NW: higher leptin (p < 0.001), lower ghrelin and adiponectin (p = 0.004, p = 0.015, respectively), and trend for higher insulin (p = 0.06).

Conclusion

This study indicates that significant differences in both pre- and selected post- prandial levels of leptin, ghrelin, adiponectin and insulin exist between NW and SO women. Improving our understanding of the biochemical mechanisms accounting for these differences in appetite hormones among individuals with varying body size and adiposity should aid in the development of future therapies to prevent and treat obesity.

     

Determinants of free-living energy expenditure in normal weight and obese women measured by doubly labeled water

Total free-living energy expenditure (TEE) was measured in 9 normal weight controls and 5 obese women using the doubly labeled water (DLW) method. Resting energy expenditure (REE) and the thermic effect of food (TEF) were measured by indirect calorimetry and the energy cost of physical activity (PA) calculated by deduction, in order to quantify the components and identify determinants of free-living TEE. Although REE was quantitatively the major component of TEE in both groups, PA best explained the variability, contributing 76% to the variance in free-living TEE. The obese women had elevated values for TEE (12397 +/- 2565 vs. 8339 +/- 1787 kJ/d, mean +/- SD; p < 0.005), compared with the control women. PA (5071 +/- 2385 vs. 2552 +/- 1452; p < 0.05) and REE (6393 +/- 678 vs. 5084 +/- 259; p < 0.0005) were also raised in the obese, whereas TEF was not significantly different between the groups, accounting for 7.6% of energy expenditure for the obese and 8% for the control subjects. Body weight was the single best determinant of mean daily free-living TEE across both groups. We conclude that PA and body weight are the main determinants of free-living TEE.     

Perceived weight status in normal weight and overweight women

The current study sought to assess women's knowledge of what objectively constitutes underweight, normal weight, or overweight for a given height, and how this knowledge is affected by a woman's own weight status. A total of 31 normal weight women and 20 overweight women were asked to provide predictions of weight ranges for a female 4 feet 11 in. to 6 feet 2 in. in height for the following categories: extremely underweight, underweight, normal weight, overweight, obese, and extremely obese. Each participant completed the questionnaire for all heights, although the critical values for each participant were the weight ranges given for their own height category. These predictions were then compared to the participants' own weight status using Body Mass Index (BMI). Results suggest that normal weight women tend to believe that women must be smaller in order to be classified as normal weight, overweight, or obese when compared to the objective BMI categories used by physicians and researchers. In other words, the normal weight participants underestimated the BMI ranges for the normal weight, overweight, and obese categories. Overall, the overweight participants were fairly accurate in their BMI predictions for the different weight categories. One implication of these findings is that normal weight women may have a bias toward overestimating their weight to be within an overweight range. The need for health care marketing efforts to increase awareness of objective weight categories is addressed.     

Metabolically obese normal weight and phenotypically obese metabolically normal youths: the CASPIAN Study

OBJECTIVES: The objectives of this study were to estimate the prevalence and distribution of cardiovascular risk factors and the metabolic syndrome in children with generalized, central, or combined types of obesity and to possibly discover if a phenotypically obese metabolically normal and a metabolically obese normal weight phenotype could be identified in children and adolescents. DESIGN: This cross-sectional study is the baseline survey of a national longitudinal study. SUBJECT/SETTING: Overall 4,811 nationally representative children, aged 6 to 18 years, were recruited from the community through randomly selected schools within six provinces in Iran. In addition to physical examination, fasting glucose and lipid profile were assessed. MAIN OUTCOME MEASURE: Obesity type was considered the independent variable, cardiovascular risk factors and the metabolic syndrome were dependent variables. Prevalence of risk factors in different types of obesity was compared by multivariate analysis of variance and post-hoc tests. Logistic regression analysis was used to examine the associations between obesity type and the metabolic syndrome. RESULTS: Varying with age and sex groups, 6% to 9% of children were categorized into the isolated central obesity group, 7.5% to 11% into the isolated generalized obesity, and 14% to 16.5% into the combined type group. The prevalence of dyslipidemia, high blood pressure, and metabolic syndrome was higher in those children with combined obesity than in those with the other two types of obesity, as well as in the central than in the generalized obesity groups. Phenotypically obese metabolically normal subjects were more prevalent in the generalized obesity group. The likelihood of metabolic syndrome was highest in those with combined obesity (odds ratio 3.7, 95% confidence interval 3.1 to 4), and lowest in generalized obesity group (odds ratio 2.1, 95% confidence interval 1.8 to 2.5). CONCLUSIONS: This study complements recent research about the adverse health hazards of abdominal obesity in children. The finding of metabolically obese normal weight children suggests that additional investigation for cardiovascular risk factors may be warranted in normal-weight children with an ethnic predisposition to chronic diseases.     

Knowledge, attitudes, and practices concerning infection control among travelers between Taiwan and mainland China

With an increase in the number of travelers around the world in recent years, widespread efforts to control the human-transmissible influenza and increased surveillance among poultry and humans should be given the highest priority. The purpose of this article is to describe an examination of the passengers traveling via "mini links" from Xiamen (China) to Kinmen (Taiwan) with reference to their knowledge and practice on infection control measures and satisfaction with public health policies. A survey of perceptions, attitudes, and practices was accordingly carried out. Although some research has been conducted on selected health topics and patients, little research has examined the perceptions of normal travelers. The results demonstrate that travelers' perception of risk for infection control was high; by contrast, their practices were not sufficient. The content analysis of this study also provides an empirical starting point for future research into combining travelers' knowledge and practice on disease problems with the worldwide public health policies.     

Differences in energy metabolism between normal weight 'large-eating' and 'small-eating' women.

Nine 'large-eating' (approximately 12 MJ/d) and nine 'small-eating' (approximately 5.3 MJ/d) women were selected from the population on the basis of diet and activity diaries. At rest and in the post-absorptive state the rate of oxygen consumption (VO2)/kg fat-free mass (FFM) and rate of carbon dioxide production (VCO2)/kg FFM were 9-17% higher (P < 0.05) in the 'large-eaters' than in the 'small-eaters'. As energy expenditure was increased by walking at 2.4, 3.9 and 5.4 km/h the differences between the two experimental groups for both VO2/kg FFM and VCO2/kg FFM were decreased to negligible values, but energy expended on a body-weight basis (MJ/kg per min) remained significantly higher (5-10%) in 'large-eaters'. Oral temperature was also consistently higher (up to 0.5 degrees) in this group both at rest and during sitting, standing and walking activities. Although the average thermic effect of a standardized liquid meal tended to be higher (27%; not significant) in the 'small-eaters', the other results demonstrate that the 'large-eating' females had a markedly higher rate of energy expenditure at rest and during light physical activities.     

Tyrosine-stimulated dopamine synthesis fails to affect urinary aldosterone and sodium relationship in normal weight and obese women

The effect of L-tyrosine-induced increases in dopamine (DA) and norepinephrine (NE) turnover on the relationship between sodium and aldosterone excretion was assessed in normal weight and obese women adapting to a low sodium diet. During four continuous days, all study subjects consumed a liquid diet, Ensure^®, as the main nutrient source, which provided an average daily intake of 51 mmol sodium. In six normal weight controls, urinary DA and NE metabolites were unchanged while urine sodium decreased until balance was achieved and aldosterone increased. The inverse relationship between urinary sodium and aldosterone was also present in six normal weight subjects even after tyrosine-induced increases in the urinary DA metabolite, homovanillic acid (HVA), and in the NE metabolites, vanillylmandelic acid (VMA) and 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG). Similarly, while tyrosine supplements increased urinary HVA and VMA in nine obese subjects, sodium and aldosterone remained inversely related. We conclude that tyrosine-induced variations in DA and NE synthesis and catabolism, as measured by urinary HVA, VMA and MHPG, have no effect on the expected relationship between urinary sodium and aldosterone or on the excretion of either one by obese and normal weight women, at least in the short term.     

Differences in eating and activity markers among normal weight, overweight, and obese rural women.

PURPOSE: The purpose of this study was to examine differences in healthy eating and physical activity behaviors and associated biomarkers among normal weight (body mass index [BMI] < 25), overweight (BMI 25-29.9), and obese (BMI > or = 30) rural women. METHODS: Random digit dialing was used to recruit 225 rural women (57.9 +/- 5.6 years). Measures of healthy eating and physical activity were completed on the computer during individual sessions at the rural sites. Research nurses then assessed a battery of biomarkers of activity and eating, including blood lipids, blood pressure, cardiorespiratory fitness (VO(2max)), and resting heart rate. RESULTS: Major findings were differences across weight categories in daily calories consumed and expended, daily fruit servings, daily meat group servings, high-density lipoprotein cholesterol, vital signs, and cardiorespiratory fitness. The obese women both consumed and expended significantly more calories daily than those in the other two weight groups. Obese women consumed significantly fewer fruit group servings than both the normal weight and overweight women. Obese women consumed significantly more meat group servings than overweight women. There also were significant differences in systolic blood pressure, diastolic blood pressure, resting heart rate, high-density lipoprotein cholesterol, and cardiorespiratory fitness across the three weight groups. CONCLUSIONS: This study provides evidence of major differences in some eating and activity behaviors and biomarkers across BMI groups. Major differences exist between the normal weight and overweight group as compared to the obese group.     

Physical activity,total energy expenditure,and food intake in grossly obese and normal weight women

The doubly labeled water method was used to measure average daily total energy expenditure (TEE) in 10 healthy normal weight women classified as unrestrained eaters and in 10 grossly obese women. The body mass index was 20.0 ± 1.3 kg/m² in the control group and 37.4 ± 8.1 kg/m² for the obese group. TEE was measured over a 2-week period. TEE was 2,357 ± 504 kcal/day for the controls and 3,708 ± 367 kcal/day for the obese group during a cognitive-behavioral treatment. © 1995 by John Wiley & Sons, Inc.     

A comparison of serum leptin concentrations in obese and normal weight Japanese women with regular menstrual cycle

Leptin is a protein that is synthesized and secreted from adipose tissue. We examined the changes in serum leptin level during the menstrual cycle in 5 normal and 5 obese Japanese women, and compared the data with those of serum estradiol (E2) and progesterone (P4) concentrations. Serum leptin levels were highly correlated with body mass index (BMI) and percent body fat, being higher in the obese group than in the normal group. In the obese group, serum leptin level increased in the luteal phase in parallel with the rise in the serum E2 level. In the normal group, however, there was no significant change in serum level during the menstrual cycle. These results suggested that the serum leptin levels were influenced by the phase of menstrual cycle, probably through the action of E2, in different ways for obese and non-obese women.     

Caffeine knowledge,attitudes, and practices of young women

We studied how the amount of caffeine consumed from beverages was related to knowledge about caffeine and to attitudes toward caffeine and nutrition in a sample of 63 young women. The two measurements of caffeine consumption: 1) the 24-hour recall of beverages and 2) the beverage-frequency list were highly correlated. The strongest predictor of caffeine consumption was the attitude that “it is hard to limit coffee consumption.” There was a weak positive correlation between caffeine consumption and the attitude that “it is safe for pregnant women to consume caffeine,” but there was no correlation between caffeine consumption and knowledge about caffeine. We observed a negative association between knowledge about caffeine and attitude toward use of caffeine during pregnancy, but we found no relationship between knowledge about caffeine and attitude toward the importance of nutrition.     

Obese women's perceptions of their physicians' weight management attitudes and practices

BACKGROUND: Obesity has reached epidemic proportions in the United States. Primary care physicians will see increasing numbers of patients with long-term weight management problems. OBJECTIVE: To examine obese women's perceptions of their physicians' weight management attitudes and practices. DESIGN AND SETTING: Women who participated in obesity trials at a university clinic completed a questionnaire that assessed their views of weight control provided by their primary care physician. PARTICIPANTS: The patients were 259 women whose age was 44.0 +/- 10.0 years; weight, 96.7 +/- 13.2 kg; and body mass index (calculated as weight in kilograms divided by the square of height in meters), 35.2 +/- 4.5 (all data given as mean +/- SD). MAIN OUTCOME MEASURES: Using 7-point scales (1 indicates low; and 7, high), patients rated their satisfaction with care provided for their general health and that for their obesity. They also identified methods their physician recommended for weight management and the frequency of negative interactions with their physician concerning weight control. RESULTS: Participants were generally satisfied with the care they received for their general health and with their physicians' medical expertise (mean scores, 6. 1 and 6.2, respectively). They were significantly (P<.001) less satisfied with care for their obesity and with their physicians' expertise in this area (mean scores, 4.1 and 4.3, respectively). Almost 50% reported that their physician had not recommended any of 10 common weight loss methods, and 75% indicated they looked to their physician a "slight amount" or "not at all" for help with weight control. Only a small minority of patients (0.4%-8.0%) reported frequent, negative interactions with physicians concerning their weight. CONCLUSIONS: The last finding helps allay concerns that obese patients are routinely treated disrespectfully by physicians when discussing weight. The challenge, however, for primary care physicians appears to be providing patients better assistance with weight management.