Gallbladder contractility in patients with cirrhotic versus malignant ascites

PURPOSE: The aim of this study was to evaluate differences in gallbladder contractility by measuring gallbladder wall thickness, fasting and residual gallbladder volume, and gallbladder ejection fraction in patients with cirrhotic and malignant ascites. METHODS: Twenty-four patients (16 women and 8 men) with malignant ascites (2 cervical, 2 colon, 2 stomach, 6 pancreatic, and 12 ovarian carcinomas), aged 59 +/- 12 years, and 26 patients (14 women and 12 men) with cirrhotic ascites, aged 57 +/- 16 years, were included in the study. After patients fasted overnight for 8 hours, gallbladder wall thickness, fasting gallbladder volume, and gallbladder volume and ejection fraction were measured sonographically at 10, 20, 30, 40, 50, 60, 70, 80, and 90 minutes after ingestion of a standard liquid test meal. RESULTS: The mean gallbladder wall thickness was higher in patients with cirrhotic ascites than in those with malignant ascites (5.5 +/- 1.5 mm [standard deviation] versus 3.1 +/- 0.6 mm, respectively; p < 0.001). The mean fasting gallbladder volume was also higher in patients with cirrhotic ascites than in those with malignant ascites (27.3 +/- 11.5 cm(3) versus 17.6 +/- 8.9 cm(3); p < 0.05). Patients with cirrhotic ascites had significantly higher mean postprandial gallbladder volumes and ejection fractions than did those with malignant ascites at all times except 10 minutes after the meal (p < 0.05). CONCLUSIONS: Our findings suggest that gallbladder contractility is greater in patients with cirrhotic ascites than in patients with malignant ascites.     

Effects of exercise on gallbladder volume and motility in obese women

PURPOSE: Comparatively few prospective studies have investigated the relationship between physical activity and gallbladder motility, and the results are controversial. Exercise may affect gallbladder motility via neural or hormonal mechanisms. The purpose of this study was to evaluate the possible effects of aerobic exercise on gallbladder motility in a group of obese women without gallstones. PATIENTS AND METHODS: Twenty-three obese women (age 41.2+/-10.3 years, body mass index 40.7+/-6.7 kg/m(2)) were included in the study. Following an overnight fast, fasting and postprandial (15, 30, 45, 60, 75, 90, 120, and 150 minute) volumes and ejection fractions were evaluated with real-time ultrasonography before exercise. For all subjects, the exercise regimen consisted of daily 45-minute walking sessions at 60-80% of maximum heart rate for 4 weeks except weekends. Gallbladder volume and ejection fraction were again evaluated after exercise. RESULTS: Fasting and postprandial (15, 30, 45, 60, 75, 90, 120, and 150 minute) volumes were 38.6+/- 10.9, 32.8+/- 8.8, 27.6/- 8.1, 22.7+/- 8.5, 21.4+/- 7.2, 20.8+/- 7.0, 22.8+/- 7.3, 29.6 +/- 7.0, and 36.8+/- 6.2 cm(3) before the exercise period, respectively, and 40.8+/- 18.9, 29.9+/-11.2, 25.3+/- 9.2, 22.4+/-8.5, 19.6+/-7.8, 17.7+/- 6.8, 17.8+/- 7.3, 23.1+/-10.8, and 29.0+/-14.4 cm(3) after the exercise period, respectively. Postprandial (15, 30, 45, 60, 75, 90, 120, and 150 minute) ejection fractions were 13.5+/-15.9, 27.4+/-15.4, 39.5+/-20.0, 43.2+/-16.7, 44.3+/-17.3, 37.5 +/- 23.5, 23.5 +/-25.1, and 5.5+/- 21.6% before the exercise period, respectively, and 22.6+/- 20.1, 34.6+/-14.5, 42.0+/-13.6, 49.2+/-12.6, 53.1+/-14.1, 52.6+/-16.1, 43.6+/-17.0, and 29.2+/- 26.5% after exercise, respectively. After the exercise period, the 75, 90, 120, and 150 minute volumes were lower (p< 0.05, p< 0.05, p< 0.05, p< 0.01) and the 90, 120, and 150 minute ejection fractions were higher than before exercise (p< 0.05, p < 0.05, p< 0.01). CONCLUSIONS: Our study showed that exercise decreased late-phase postprandial gallbladder volume and increased late-phase postprandial gallbladder motility in these obese women.     

Gallbladder emptying in diabetic patients and control subjects assessed by real-time ultrasonography and cholescintigraphy: a methodological comparison

Gallbladder motor function was studied in nine diabetic patients and nine control subjects matched for sex, age, and weight. None of the subjects had gallstones. Two different techniques were employed: real-time ultrasonography and cholescintigraphy using 99mTc-HIDA as imaging agent. Gallbladder volumes were determined sonographically by using three dimensions: length, lateral, and anterior-posterior diameters. Gallbladder emptying was stimulated by a standard test drink (Biloptin). Ejection fraction was computed and the results obtained by both techniques were compared. Fasting and residual gallbladder volumes after contraction were significantly larger in the diabetic patients than in the control subjects (15.9 +/- 7.6 cm3 vs. 2.3 +/- 1.3 cm3, p less than .0007; and 9.2 +/- 9.8 cm3 vs. 0.7 +/- 0.7 cm3, p less than .0007). Ejection fractions (ultrasonography/cholescintigraphy) were lower in the diabetic patients compared with the control subjects (59.9 +/- 26.6% and 63.1 +/- 23.2% vs. 73.2 +/- 23.8% and 75.3 +/- 24.8%), however, this difference was not statistically significant. Sonographically and scintigraphically determined ejection fractions were closely correlated (r = 0.90, p less than .00005).     

Sex differences in African-Americans regarding sensitivity to insulin's glucoregulatory and antilipolytic actions.

OBJECTIVE: The purpose of this study was to determine if there are sex differences in African-Americans regarding the effect of obesity on sensitivity to insulin as a glucoregulatory and antilipolytic hormone. RESEARCH DESIGN AND METHODS: Data from study participants, 127 nondiabetic African-Americans (mean age 32 +/- 4 years), included anthropometric measurements, an oral glucose tolerance test (OGTT), a 2-h euglycemic-hyperinsulinemic clamp, and a fasting triglyceride level. Sensitivity to insulin as a glucoregulatory hormone was determined by M/FFM, where M is the mean glucose infusion rate during the second hour of the clamp and FFM is fat-free mass. Sensitivity to insulin's antilipolytic action was assessed during the OGTT by the percent suppression of free fatty acid (FFA) concentrations between 0 and 120 min. The higher the suppression of FFAs, the greater the sensitivity to insulin's antilipolytic action. RESULTS: The participants were classified by BMI into three groups: nonobese (31 men, 24 women), obese (17 men, 14 women), and severely obese (12 men, 29 women). The women had higher percentages of body fat (P < 0.001), and the men had greater FFM (P < 0.001). The M/FFM values for men versus women in each BMI group were nonobese, 8.8 +/- 2.8 vs. 10.8 +/- 4.4; obese, 7.2 +/- 3.4 vs. 8.5 +/- 3.4; and severely obese, 4.7 +/- 2.1 vs. 6.1 +/- 2.2. The difference between the BMI groups was significant (P < 0.001), as was the difference between men and women (P < 0.01). In addition, there was a significant sex difference in percent suppression of FFAS (P < 0.001). The men and women had similar fasting insulin and FFA concentrations; however, in the men only, the percent suppression of FFA declined with increasing obesity (nonobese, 83 +/- 15%; obese, 73 +/- 18%; and severely obese, 69 +/- 19%; P = 0.02). The women in all three BMI groups had lower FFA levels of 86-88%. CONCLUSIONS: Obese African-American men and women are resistant to insulin as a glucoregulatory hormone, but only obese men are resistant to insulin's antilipolytic action; obese African-American women are sensitive to insulin's antilipolytic action. The combined presence of sensitivity to insulin's antilipolytic action with resistance to insulin's glucoregulatory action in obese African-American women may contribute to their high prevalence of obesity and type 2 diabetes.     

Effect of obesity and weight reduction on biliary cholesterol saturation and the response to chenodeoxycholic acid

Biliary cholesterol saturation indices (SI's) were measured in fasting duodenal bile from (i) obese and non-obese individuals with and without cholesterol gallstones, (ii) obese individuals undergoing weight reduction and (iii) obese gallstone patients receiving chenodeoxycholic acid (CDCA) therapy. Biliary lipid secretion rates were also measured in three obese subjects before and during 11 days starvation. The mean SI in fifteen non-obese controls (0.89 +/- SEM 0.06) was significantly lower than that in the twenty-four obese without (1.14 +/- 0.07; P less than 0.01), and in the twenty-nine non-obese with gallstones (1.30 +/- 0.05; P less than 0.001) while in sixteen obese gallstone patients, the mean SI of 1.55 +/- 0.06 was significantly higher than that seen in the other three groups (P less than 0.01-0.001). Although fifteen obese subjects lost 15% of their initial body weight during dieting, this did not change their SI's consistently. However in three obese individuals, total starvation did reduce the SI's and significantly lowered the biliary cholesterol secretion rate. Ten obese gallstone patients responded to 15.8 +/- 0.3 mg CDCA kg-1 day-1 by developing unsaturated fasting duodenal bile (SI 0.89 +/- 0.04). A further increase in CDCA dose to 19.0 +/- 0.7 mg kg-1 day-1, as a result of reducing body weight, was more effective in lowering SI's (0.75 +/- 0.06, range 0.51-1.0) than that achieved by increasing the dose to 18.9 +/- 0.46 mg kg-1 day-1 through more capsules per day (SI 0.89 +/- 0.03, range 0.67-1.25). These studies show that (i) biliary cholesterol SI's are greater when obesity and gallstones occur together than in either obesity or gallstones alone, and (ii) although weight loss in obese individuals does not consistently alter biliary cholesterol SI's, it may be beneficial in obese patients receiving CDCA therapy for gallstone dissolution.     

Effects of ear points' pressing on parameters related to obesity in non-obese healthy and obese volunteers

OBJECTIVES: The aim of this study was to evaluate the effects of ear points' pressing at ear meridian points on the following obesity-related parameters: body weight; body fat; body-mass index; waist; hip circumference (HC); and waist circumference (WC)/HC ratio between two groups of subjects, nonobese healthy and obese volunteers. METHODS: The study was an open-parallel randomized controlled trial and the sample consisted of 31 nonobese healthy (BMI < 27 kg/m(2)) volunteers and 7 obese (BMI > or = 27 kg/m(2)) volunteers who were randomly divided into two groups. In the treatment group, ear points' pressing at 5 ear meridian points was applied, while volunteers in the control group did not receive any intervention. At baseline and each week of the 9-week study, the outcomes mentioned above were examined in all volunteers. RESULTS: There was a statistically significant drop in WC and HC during the 9-week treatment in the treatment and the control group in the healthy volunteers. In the treatment group, WC decreased from 77.63 +/- 11.95 cm to 75.06 +/- 12.21 cm (p = 0.005) and HC dropped from 99.10 +/- 9.46 cm to 96.75 +/- 11.35 cm (p = 0.005). In the control group, WC decreased from 77.51 +/- 11.96 cm to 75.23 +/- 10.76 cm (p = 0.001) and HC dropped from 99.70 +/- 7.72 cm to 97.66 +/- 8.39 cm (p = 0.002). Then, when a subgroup analysis in healthy and obese volunteers was performed, it produced. It showed the same result-a statistically significant drop in WC and HC in healthy volunteers, while no significant drop was found in obese volunteers. CONCLUSIONS: Even though the result showed a statistically significant drop in WC and HC during the 9-week treatment in both the treatment and control groups of healthy volunteers, there was no statistically significant change in outcomes in the obese group. Further studies are needed to detect the effect of ear points' pressing by increasing sample sizes and conducting randomized control trials with both healthy and obese volunteers.     

Leptin secretion from adipose tissue in women. Relationship to plasma levels and gene expression.

The role of expression and secretion of the ob gene product, leptin, for the regulation of plasma leptin levels has been investigated in vitro using abdominal subcutaneous adipose tissue of 20 obese, otherwise healthy, and 11 nonobese women. Body mass index (BMI, mean+/-SEM; kg/m2) in the two groups was 41+/-2 and 23+/-1, respectively. Fat cell volume was 815+/-55 pl in the obese and 320+/-46 pl in the nonobese group. In the obese group, plasma leptin concentrations and adipose leptin mRNA (relative to gamma actin) were increased five and two times, respectively. Moreover, adipose tissue secretion rates per gram lipid weight or per fat cell number were also increased two and seven times, respectively, in the obese group. There were strong linear correlations (r = 0.6-0.8) between plasma leptin, leptin secretion, and leptin mRNA. All of these leptin measurements correlated strongly with BMI and fat cell volume (r = 0.7- 0.9). About 60% of the variation in plasma leptin could be attributed to variations in leptin secretion rate, BMI, or fat cell volume. We conclude that elevated circulating levels of leptin in obese women above all result from accelerated secretion rates of the peptide from adipose tissue because of increased ob gene expression. However, leptin mRNA, leptin secretion, and circulating leptin levels are all more closely related to the stored amount of lipids in the fat cells of adipose tissue than they are to an arbitrary division into obese versus nonobese.     

Calcium in human gallbladder bile.

Biliary calcium is believed to be of great importance in gallstone pathogenesis. These studies were therefore performed to determine if quantitative and/or qualitative differences in calcium are present in gallbladder bile from patients with and without gallstones. Bile was obtained by direct gallbladder aspiration from 68 obese patients undergoing elective gastric bypass surgery. Forty-five patients had no evidence of gallstones or sludge, 18 had cholesterol gallstones, and five had black pigment stones. Gallbladder bile was also obtained from 27 nonobese patients undergoing elective cholecystectomy (19 cholesterol; eight black pigment gallstones). For all patients, total calcium ranged from 1.50 to 16.44 mmol/L (mean: 6.05 +/- 0.31 mmol/L); free Ca++ ion ranged from 0.53 to 2.83 mmol/L (mean: 1.28 +/- 0.05 mmol/L). Considerable overlap was observed between obese and nonobese subjects and between patients with and without gallstones. For all patient groups, calcium, Ca++, and bound calcium increased linearly with increasing concentrations of bile salt. No significant differences in the slopes of these relationships were observed with obesity or gallstones. In contrast, free Ca++ ion was greater in gallbladder bile from gallstone patient groups throughout the entire range of bile salt. We hypothesize that this observed increase in Ca++ resulted from increased Gibbs-Donnan forces and excess gallbladder mucin present within the gallbladder bile of patients with gallstones.     

Influence of body fat distribution on free fatty acid metabolism in obesity.

In order to determine whether differences in body fat distribution result in specific abnormalities of free fatty acid (FFA) metabolism, palmitate turnover, a measure of systemic adipose tissue lipolysis, was measured in 10 women with upper body obesity, 9 women with lower body obesity, and 8 nonobese women under overnight postabsorptive (basal), epinephrine stimulated and insulin suppressed conditions. Results: Upper body obese women had greater (P less than 0.005) basal palmitate turnover than lower body obese or nonobese women (2.8 +/- 0.2 vs. 2.1 +/- 0.2 vs. 1.8 +/- 0.2 mumol.kg lean body mass (LBM)-1.min-1, respectively), but a reduced (P less than 0.05) net lipolytic response to epinephrine (59 +/- 7 vs. 79 +/- 5 vs. 81 +/- 7 mumol palmitate/kg LBM, respectively). Both types of obesity were associated with impaired suppression of FFA turnover in response to euglycemic hyperinsulinemia compared to nonobese women (P less than 0.005). These specific differences in FFA metabolism may reflect adipocyte heterogeneity, which may in turn affect the metabolic aberrations associated with different types of obesity. These findings emphasize the need to characterize obese subjects before studies.     

Association between regional adipose tissue distribution and both type 2 diabetes and impaired glucose tolerance in elderly men and women

OBJECTIVE: We examined whether regional adipose tissue distribution, specifically that of skeletal muscle fat and visceral abdominal fat aggregation, is characteristic of elderly individuals with hyperinsulinemia, type 2 diabetes, and impaired glucose tolerance (IGT). RESEARCH DESIGN AND METHODS: A total of 2,964 elderly men and women (mean age 73.6 years) were recruited for cross-sectional comparisons of diabetes or glucose tolerance, generalized obesity with dual-energy X-ray absorptiometry, and regional body fat distribution with computed tomography. RESULTS-Approximately one-third of men with type 2 diabetes and less than half of women with type 2 diabetes were obese (BMI > or =30 kg/m(2)). Despite similar amounts of subcutaneous thigh fat, intermuscular fat was higher in subjects with type 2 diabetes and IGT than in subjects with normal glucose tolerance (NGT) (11.2 +/- 9.4, 10.3 +/- 5.8, and 9.2 +/- 5.9 cm(2) for men; 12.1 +/- 6.1, 10.9 +/- 6.5, and 9.4 +/- 5.3 cm(2) for women; both P < 0.0001). Visceral abdominal fat was also higher in men and women with type 2 diabetes and IGT than in subjects with NGT (172 +/- 79, 163 +/- 72, and 145 +/- 66 cm(2) for men; 162 +/- 66, 141 +/- 60, and 116 +/- 54 cm(2) for women; both P < 0.0001 across groups). Higher rates of intermuscular fat and visceral abdominal fat were associated with higher fasting insulin in normal-weight (BMI <25 kg/m(2)) men (r = 0.24 for intermuscular fat, r = 0.37 for visceral abdominal fat, both P < 0.0001) and women (r = 0.20 for intermuscular fat, r = 0.40 for visceral abdominal fat, both P < 0.0001). These associations were not found in obese subjects. CONCLUSIONS: Elderly men and women with normal body weight may be at risk for metabolic abnormalities, including type 2 diabetes, if they possess an inordinate amount of muscle fat or visceral abdominal fat.     

Regulation of forearm lipolysis in different types of obesity. In vivo evidence for adipocyte heterogeneity.

Forearm and systemic adipose tissue free fatty acid (FFA) release was measured in eight nonobese, six lower-body obese, and eight upper-body obese women under basal, hyperinsulinemic, and hypoinsulinemic conditions to determine whether forearm fat is regulated in a similar manner as whole body fat. Results: Adipose tissue palmitate release was greater from forearm than whole body (5.97 +/- 0.75 vs. 3.84 +/- 0.34 mumol.kg fat-1.min-1, respectively, P less than 0.005, n = 22 subjects). Systemic palmitate release, relative to fat mass, was significantly (P less than 0.01) greater in nonobese than upper-body obese, and upper-body obese than lower-body obese women, and forearm adipose tissue palmitate release followed the same pattern. Hyperinsulinemia suppressed systemic and forearm lipolysis to similar degrees, however, hypoinsulinemia consistently increased systemic palmitate flux without increasing forearm palmitate release. These results confirm the heterogeneity of adipose tissue in an in vivo model and emphasize the need to consider which adipose tissue depots are responsible for the differences in systemic FFA flux in obese and nonobese humans.     

Metabolic predictors of obesity. Contribution of resting energy expenditure, thermic effect of food, and fuel utilization to four-year weight gain of post-obese and never-obese women.

This prospective study was designed to identify abnormalities of energy expenditure and fuel utilization which distinguish post-obese women from never-obese controls. 24 moderately obese, postmenopausal, nondiabetic women with a familial predisposition to obesity underwent assessments of body composition, fasting and postprandial energy expenditure, and fuel utilization in the obese state and after weight loss (mean 12.9 kg) to a post-obese, normal-weight state. The post-obese women were compared with 24 never-obese women of comparable age and body composition. Four years later, without intervention, body weight was reassessed in both groups. Results indicated that all parameters measured in the post-obese women were similar to the never-obese controls: mean resting energy expenditure, thermic effect of food, and fasting and postprandial substrate oxidation and insulin-glucose patterns. Four years later, post-obese women regained a mean of 10.9 kg while control subjects remained lean (mean gain 1.7 kg) (P < 0.001 between groups). Neither energy expenditure nor fuel oxidation correlated with 4-yr weight changes, whereas self-reported physical inactivity was associated with greater weight regain. The data suggest that weight gain in obesity-prone women may be due to maladaptive responses to the environment, such as physical inactivity or excess energy intake, rather than to reduced energy requirements.     

Impaired fatty-meal-stimulated gallbladder contractility in patients with Crohn's disease.

1. The incidence of gallstones in patients with Crohn's disease is increased compared with that in healthy control subjects. This is in part due to reduced terminal ileal bile salt absorption and consequent increased cholesterol saturation in bile. The aim of this study was to evaluate gallbladder contractility, a second important factor in the pathogenesis of gallstones, in Crohn's disease. 2. Thirty patients with Crohn's disease and no known biliary tract disease and nine healthy control subjects were studied. After an overnight fast, gallbladder volume was determined by real-time ultrasonography before and 10, 20, 30, 40, and 50 min after ingestion of a standard liquid fatty meal. 3. Compared with healthy control subjects, patients with Crohn's disease had similar fasting gallbladder volumes (control, 18.7 +/- 2.3 ml; Crohn's disease, 18.2 +/- 2.3 ml). Percentage emptying was significantly impaired at 30, 40 and 50 min in patients with Crohn's disease compared with control subjects. Patients with Crohn's disease limited to the small bowel had gallbladder contractility that was comparable with that of control subjects, whereas in those with large-bowel disease, minimum residual gallbladder volume was significantly smaller than in control subjects. Patients with both large- and small-bowel Crohn's disease demonstrated the most marked abnormalities, with gallbladder volumes significantly larger than those of control subjects at 30, 40 and 50 min. Likewise, patients with Crohn's disease who had undergone previous bowel resection had impaired emptying at 30, 40 and 50 min.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma homocysteine levels in obese and non-obese subjects with or without hypertension; its relationship with oxidative stress and copper

OBJECTIVES: The relationship between plasma total Homocysteine (tHcy) and oxidative stress and plasma levels of lipids, insulin and copper levels were investigated in obese and nonobese hypertensives. DESIGN AND METHODS: Plasma tHcy levels were determined by an enzyme immunoassay method. Plasma lipid peroxidation levels were measured as thiobarbituric acid reactive substances (TBARS) by spectrophotometric methods. Plasma levels of copper and insulin were measured by atomic absorption spectrophotometer and electrochemiluminescence method, respectively. RESULTS: Plasma tHcy, copper and insulin levels did not differ in nonobese hypertensives compared to nonobese normotensives. Plasma TBARS levels were significantly increased in nonobese hypertensives when compared to nonobese normotensives (p < 0.001). Plasma tHcy, TBARS, copper and fasting insulin levels were significantly higher in obese normotensives and hypertensives than in nonobese normotensives and hypertensives, respectively (for each comparison; p < 0.001). There was a significant difference in plasma tHcy, TBARS and copper levels between obese subjects with or without hypertension (for each comparison p < 0.01). The univariate analyses demonstrated a significant positive correlation between tHcy and TBARS (coefficient +/- SE, 0.411 +/- 0.115, p < 0.01) and copper (coefficient +/- SE, 0.425 +/- 0.135, p < 0.01) in obese subjects. In a multivariate regression analysis in obese subjects tHcy was positively correlated with TBARS (coefficient +/- SE, 0.480 +/- 0.155, p < 0.01) and copper (coefficient +/- SE, 0.486 +/- 0.140, p < 0.01). CONCLUSIONS: We hypothesize that in the presence of other traditional risk factors, Hcy may have a permissive role in the endothelium damage even within the normal range and this role may be related to free radical generating systems. Therefore, modest elevation of plasma Hcy may causally be involved in the pathogenesis of atherosclerosis and/or cardiovascular disease.     

Sonographic assessment of changes in thickness of different abdominal fat layers in response to diet in obese women

PURPOSE: We evaluated the potential application of sonography to monitor alterations in abdominal fat thickness in obese women before and after dieting. METHODS: This study included 40 obese women (mean age, 42.2 +/- 9.4 years; mean body mass index [BMI], 36.0 +/- 5.9 kg/m2) who underwent a 3-month low-calorie diet. Height, weight, waist circumference (WC), and hip circumference (HC) were measured. BMI and waist-to-hip ratio (WHR) were calculated. Abdominal subcutaneous (S) and intra-abdominal preperitoneal (P) fat were measured at their maximum (max) and minimum (min) thickness sites using a 7.5-MHz linear-array probe. Intra-abdominal visceral (V) fat was measured using a 3.5-MHz convex-array probe. Measurements were taken before and after caloric restriction. RESULTS: The mean weight was reduced from 88.6 +/- 17.1 kg to 83.0 +/- 15.9 kg (p < 0.0001). The mean changes in S(min) (r = 0.376, p = 0.017), S(max) (r = 0.508, (p = 0.001), P(min) (r = 0.439, p = 0.005), and V (r = 0.365, p = 0.022) fat thicknesses were positively correlated with change in weight; the change in P(max) fat thickness showed the best and most significant correlation (r = 0.591, p < 0.0001). BMI (r = 0.969, p < 0.0001), WC (r = 0.510, p = 0.001), and HC (r = 0.422, p = 0.007) changes were also positively correlated with weight change, but the WHR change (r = 0.019, p > 0.05) was not. CONCLUSIONS: All the abdominal fat layers, particularly the intra-abdominal P fat, will decrease in response to loss of body fat by dieting. Sonography seems to be useful in monitoring small variations in the thicknesses of abdominal S and intra-abdominal P and V fat.     

Evidence for alteration of the vitamin D-endocrine system in obese subjects.

Serum immunoreactive parathyroid hormone (PTH) is increased in obese as compared with nonobese subjects and declines with weight loss. To determine whether alteration of the vitamin D-endocrine system occurs in obesity and whether ensuing secondary hyperparathyroidism is associated with a reduction in urinary calcium, a study was performed in 12 obese white individuals, five men and seven women, and 14 nonobese white subjects, eight men and six women, ranging in age from 20 to 35 yr. Body weight averaged 106 +/- 6 kg in the obese and 68 +/- 2 kg in the nonobese subjects (P less than 0.01). Each of them were hospitalized on a metabolic ward and were given a constant daily diet containing 400 mg of calcium and 900 mg of phosphorus. Whereas mean serum calcium, serum ionized calcium, and serum phosphorus were the same in the two groups, mean serum immunoreactive PTH (518 +/- 48 vs. 243 +/- 33 pg/ml, P less than 0.001), mean serum 1,25-dihydroxyvitamin D [1,25(OH)2D] (37 +/- 2 vs. 29 +/- 2, P less than 0.01), and mean serum Gla protein (33 +/- 2 vs. 24 +/- 2 ng/ml, P less than 0.02) were significantly higher, and mean serum 25-hydroxyvitamin D (25-OHD) (8 +/- 1 vs. 20 +/- 2 ng/ml, P less than 0.001) was significantly lower in the obese than in the nonobese men and women. Mean urinary phosphorus was the same in the two groups, whereas mean urinary calcium (115 +/- 10 vs. 166 +/- 13 mg/d, P less than 0.01) was significantly lower, and mean urinary cyclic AMP (3.18 +/- 0.43 vs. 1.84 +/- 0.25 nM/dl GF, P less than 0.01) and creatinine clearance (216 +/- 13 vs. 173 +/- 6 liter/d, P less than 0.01) were significantly higher in the obese than in the nonobese individuals. There was a significant positive correlation between percentage of ideal body weight and urinary cyclic AMP (r = 0.524, P less than 0.01) and between percentage of ideal body weight and serum immunoreactive PTH (r = 0.717, P less than 0.01) in the two groups. The results provide evidence that alteration of the vitamin D-endocrine system in obese subjects is characterized by secondary hyperparathyroidism which is associated with enhanced renal tubular reabsorption of calcium and increased circulating 1,25(OH)2D. The reduction of serum 25-OHD in them is attributed to feedback inhibition of hepatic synthesis of the precursor by the increased serum 1,25(OH)2D.     

Effects of body fat distribution on regional lipolysis in obesity.

To determine the contribution of the major body fat depots to systemic free fatty acid (FFA) availability, palmitate ([1-14C]-palmitate) release was measured from leg (lower body) and non-leg (upper body) fat in eight upper body obese (UB Ob), six lower body obese (LB Ob), and six nonobese (Non Ob) age-matched premenopausal women in the overnight postabsorptive state. Splanchnic palmitate release was determined in 16 of these subjects. Results: total palmitate release was greater in UB Ob (P less than 0.005) than LB Ob or Non Ob women (161 +/- 16 vs. 111 +/- 9 vs. 92 +/- 9 mumol/min, respectively). Despite increased leg fat mass in obese women, leg palmitate release was similar in each group. Therefore, leg fat palmitate release was greater in Non Ob women than LB Ob (P less than 0.01) or UB Ob (P = 0.06) women (3.7 +/- 0.3 vs. 2.4 +/- 0.2 vs. 2.7 +/- 0.2 mumol.kg fat-1.min-1, respectively). Upper body fat palmitate release was less (P less than 0.01) in LB Ob than Non Ob or UB Ob women (3.0 +/- 0.4 vs. 5.0 +/- 0.3 vs. 4.9 +/- 0.4 mumol.kg fat-1.min-1, respectively). Splanchnic palmitate release accounted for 20-32% of upper body fat palmitate release in each group (P = NS between groups). Leg fat palmitate release was significantly less than upper body fat palmitate release. We conclude that the major difference in resting FFA metabolism between UB Ob and LB Ob women is the ability of the later to down-regulate upper body fat lipolysis to maintain normal FFA availability.     

Association of lung volumes with nocturnal oxygen saturation in obese persons: a possible role for therapeutic continuous positive airway pressure

We investigated the association among obesity, nocturnal oxygen saturation, and pulmonary function in 31 obese women and 17 obese men scheduled for bariatric surgery who underwent nocturnal polysomnography and pulmonary function testing. Pearson correlation coefficients showed a significant association between expiratory reserve volume percent and average oxygen saturation (P = 0.027), between body mass index and lowest oxygen saturation (P = 0.034), and between body mass index and average oxygen saturation (P = 0.039). The mean age, body mass index, expiratory reserve volume percent, and functional residual capacity percent were not significantly different between obese women and men. The lowest oxygen saturation was 80 +/- 10% in obese women and 62 +/- 19% in obese men (P = 0.001). The average oxygen saturation was 88 +/- 5% in obese women and 83 +/- 6% in obese men (P = 0.005) Therapeutic nocturnal continuous positive airway pressure may have a role by improving ventilation-perfusion matching and thereby improving nocturnal oxygen saturation in these patients.     

Correlation of MRI liver volume and doppler sonographic portal hemodynamics with histologic findings in patients with chronic hepatitis C

PURPOSE: The purpose of this study was to correlate portal hemodynamics on sonography and liver volume on MRI with histologic findings in asymptomatic patients with chronic hepatitis C. METHODS: Portal blood flow in the left and right portal branches in 20 healthy volunteers and in 26 patients was measured using Doppler sonography during both fasting and postprandial states. Total liver and right-and left-lobe volumes were determined using MRI. The ratio between portal blood flow and liver volume determined the "portal flow index" of the right and left lobes. RESULTS: We observed a statistically significant difference (p < 0.01) between the volunteers and patients in the mean left-lobe volume (352 +/- 81 cm(3) versus 544 +/- 159 cm(3)) and in the mean left portal flow index (1.1 +/- 0.2 ml/minute/cm(3) versus 0.69 +/- 0.2 ml/minute/cm(3)) as measured before the subjects ate. After a meal, the portal blood-flow volume in the right lobe was similar in the 2 groups but in the left lobe was significantly lower in the patients (p = 0.0009). The left postprandial portal flow index was inversely correlated with the grade of liver fibrosis (r = 0.533). CONCLUSIONS: The left-lobe volume (positive predictive value, 83%; negative predictive value, 72%) and left postprandial portal flow index (positive predictive value, 86%; negative predictive value, 88%) are sensitive indicators of chronic hepatitis. The left postprandial portal flow index may be a useful test for differentiating patients with minimal or no fibrosis from patients with mild to severe fibrosis.     

Impact of obesity on metabolism in men and women. Importance of regional adipose tissue distribution.

The distribution of adipose tissue thickness, fat cell weight (FCW), and number (FCN) were studied in four regions in randomly selected middle-aged men and women and in 930 obese individuals. Both the obese and the randomly selected men were found to have the largest adipose tissue thickness in the abdominal region. Women, however, showed a relative preponderance for the gluteal and femoral regions. FCW increased with expanding body fat up to a maximal size of approximately 0.7-0.8 micrograms/cell in each region. After this increase in FCW, a more rapid increase in FCN was found. For the same degree of relative overweight, men had higher triglyceride, fasting glucose, and insulin levels; higher sums of glucose and insulin levels during an oral glucose tolerance test; and higher blood pressure. Furthermore, elevated fasting glucose levels (greater than 7.4 mM) occurred twice as often in the males. These differences between males and females persisted even after body fat matching. A male risk profile was seen in women characterized by abdominal obesity (high waist/hip circumference ratio) as compared to women with the typical peripheral obesity. Stepwise multiple regression analyses in both women and men showed the obesity complications to be associated in a first step to waist/hip circumference or body fat and in a second to abdominal fat cell size. It may thus be concluded that: (a) In both obese and nonobese subjects, regional differences exist between the sexes with regard to adipose tissue distribution. (b) Moderate expansion of body fat is mainly due to FCW enlargement, which is subsequently followed by increased FCN. (c) Men and women with a male abdominal type of obesity are more susceptible to the effect of excess body fat on lipid and carbohydrate metabolism.