Wide Range Of Body Mass Index Research Articles

Ventricular hypertrophy and cavity dilatation in relation to body mass index in women with uncomplicated obesity

ObjectiveThe traditionally accepted mechanism for ventricular adaptation to obesity suggests that cavity dilatation in response to increased blood volume and elevated filling pressure results in ventricular hypertrophy as a compensatory...

Waist to Height Ratio as a Predictor of Abdominal Fat Distribution in Men

The accumulation of fat in visceral (VA) and subcutaneous abdominal adipose tissue (SA) is highly correlated with the metabolic abnormalities that contribute to increased risk of diabetes mellitus and cardiovascular disease. The purpose of the study was to determine which of the four indices-waist circumference (WC), waist-to-hip ratio (WHR), waist to height ratio (WHtR) and body mass index (BMI)-was the best predictor of VA and SA in men. We studied 111 men with a wide range of BMI, WC, WHtR, WHR and BMI determined by standard methods. SA and VA were quantified using computed tomography. In univariate and multiple regression analyses, WHtR had the highest correlation with VA and SA. To assess the relative strength of these associations, we used non-nested regression models. WHtR was a stronger predictor of SA than BMI (P = 0.02), but the relative strength of WC and BMI in predicting SA did not differ significantly (P > 0.05). WHtR was a stronger predictor of VA than WC (P = 0.012), BMI (P < 0.001) or WHR (P < 0.001). In men, WHtR is a good anthropometric index which has a stronger correlation with the distribution of visceral and subcutaneous abdominal adipose tissue than BMI or WHR. Its association is closer to or stronger than WC.

Racial differences in the association between body mass index and serum IGF1, IGF2, and IGFBP3

African-American (AA) race/ethnicity, lower body mass index (BMI), and higher IGF1 levels are associated with premenopausal breast cancer risk. This cross-sectional analysis investigated whether BMI or BMI at age 21 years contributes to racial differences in IGF1, IGF2, IGF-binding protein 3 (IGFBP3), or free IGF1. Participants included 816 white and 821 AA women between ages 40 and 79 years across a wide BMI range (18.5-40 kg/m(2)). Compared with white women, AA women had higher mean IGF1 (146.3 vs 134.4 ng/ml) and free IGF1 (0.145 vs 0.127) levels, and lower IGF2 (1633.0 vs 1769.3 ng/ml) and IGFBP3 (3663.3 vs 3842.5 ng/ml) levels (all P<0.01; adjusted for age, height, BMI, BMI at age 21 years, and menopausal status). Regardless of race, IGF1 and free IGF1 levels rose sharply as BMI increased to 22-24 kg/m(2), and then declined thereafter, while IGF2 and IGFBP3 levels tended to rise with BMI. In contrast, BMI at age 21 years was inversely associated with all IGF levels, but only among white women (P-interaction=0.01). With the decline in IGF1 with BMI at age 21 years among whites, racial differences in IGF1 significantly increased among women who were obese in early adulthood. In summary, BMI was associated with IGF1 levels regardless of race/ethnicity, while obesity during childhood or young adulthood may have a greater impact on IGF1 levels among white women. The effects of obesity throughout life on the IGF axis and racial differences in breast cancer risk require study.

Relationship between postabsorptive respiratory exchange ratio and plasma free fatty acid concentrations

The relationship between overnight postabsorptive (fasting) respiratory exchange ratio (RER) and plasma FFA concentrations was addressed using data from three separate protocols, each of which involved careful control of the antecedent diet. Protocol 1 examined the relationship between fasting RER and the previous daytime RER. In Protocol 2 fasting, RER and plasma palmitate concentrations were measured in 29 women and 31 men (body mass index <30 kg.m(-2)). Protocol 3 analyzed data from Nielsen et al. (Nielsen, S., Z. K. Guo, J. B. Albu, S. Klein, P. C. O'Brien, M. D. Jensen. 2003. Energy expenditure, sex and endogenous fuel availability in humans. J. Clin. Invest. 111: 981-988.) to understand how fasting RER and palmitate concentrations relate within individuals during four consecutive measurements. The results were as follows: 1) Fasting RER was correlated (r = 0.74, P < 0.001) with the previous day's average RER, and less so with RER variability. 2) Fasting RER was correlated (r = -0.39, P = 0.007) with fasting plasma palmitate concentrations. 3) The pattern of the RER/palmitate relationship was similar within individuals and between individuals; a negative slope was observed significantly more often than a positive slope (chi(2) test; P < 0.001). Our findings suggest that, despite a fixed food quotient, the slight departures from energy equilibrium in a controlled General Clinical Research Center environment can effect plasma FFA concentrations. We suggest that including indirect calorimetry as part of FFA metabolism studies may aid in data interpretation.

Using body mass index Z-score among severely obese adolescents: A cautionary note

Over 17% of US children aged 12-19 years are obese, leading to new issues in differentiating weight status among severely obese adolescents. Using the CDC 2000 growth curves and published equations, this study highlights the pitfalls of using body mass index (BMI) Z-score as an outcome measure in clinical research involving severely obese adolescents. Above BMIs of 40, which are typical for adolescent treatment programs, a wide range of BMI translates to a very narrow range of BMI Z-scores, and BMI Z-scores exhibit an upper limit similar to BMI percentiles. At this level, the correspondence between BMI and BMI Z-score differs by age, sex and starting BMI. Thus, a stable high BMI during adolescence results in increasing BMI Z-scores for boys and decreasing BMI Z-scores in girls. A new supplemental BMI reference may be needed specifically for severely obese adolescents to improve measurement and evaluation of treatment success in this group.

Transvaginal Endoscopic Cholecystectomy in Human Beings: Preliminary Results

The exciting concept of performing surgery in the peritoneal cavity without abdominal incisions by means of flexible endoscopes introduced through natural orifices-natural orifice transluminal endoscopic surgery (NOTES) has been widely investigated in recent years in experimental settings. However, experience with this procedure in human beings is still lacking. In this paper, we report the preliminary results of a small consecutive series of transvaginal endoscopic cholecystectomies. A standard double-channel gastroscope introduced into the abdominal cavity through a posterior colpotomy was used to perform the cholecystectomy. The introduction of a 5-mm trocar in the left-upper abdominal quadrant was mandatory to create and monitor the pneumoperitoneum and allow the application of the standard laparoscopic clips. This port was also used to introduce a grasper that assisted in the exposure of the gallbladder. The gallbladder was removed through the vagina and was protected in a plastic bag. Since July 2007, 3 patients were successfully operated on by this approach, including 1 morbidly obese woman with a body mass index (BMI) of 45. The mean operative time was 136 minutes (range, 110-190). No postoperative complications occurred, and the patients did not complain of pain at both access sites. At the 1-month follow-up, none of the patients complained of dyspareunia. The transvaginal cholecystectomy is feasible, safe, and reproducible in women within a wide range of BMI. NOTES might dramatically change the way surgery will be conceived and performed in the future, as it holds the potential to abolish the historic association of surgery with pain and scars.

Validity of thoracic gas volume equations in children of varying body mass index classifications

The aim of the study was to evaluate air-displacement plethysmography (ADP) thoracic gas volume (TGV) prediction equations in children representing a wide range of body mass index (BMI). 254 children (5 to 17 years) were recruited from two centres (England and the United States). Subjects were stratified into three BMI categories according to the International Obesity TaskForce (IOTF) criteria: lean (48 male, 42 female), overweight (15 male, 29 female), and obese (52 male, 68 female). As part of the normal ADP procedure, TGV was measured (TGV(Meas)), predicted using child specific equations developed by Fields (TGV(Fields)) and adult derived equations by Crapo (TGV(Crapo)) with percentage body fat (PF) estimates subsequently calculated (PF(Meas), PF(Fields), PF(Crapo)). Compared with the mean TGV(Meas), the TGV(Fields) estimates were within+/-0.2 L in all groups, except obese males (+0.5 L), while the mean TGV(Crapo) estimates were greater than+/-0.3 L in all groups except lean males (+0.1 L). When converted to PF, the mean PF(Fields) estimates were within+/-1% of the measured value in all groups, except obese males (+1.1%), while the mean PF(Crapo) estimates were greater than+/-1% in all groups, except lean males (+0.5%). Using either prediction equation, Bland-Altman analysis revealed that the greatest PF+/-95% limits of agreement were in the lean and overweight groups and lowest in the obese groups. The Fields child-specific TGV prediction equations provide accurate mean PF estimates and appear better than using the Crapo equations if a measured TGV cannot be achieved in children of a wide range of BMI. However, individual predictions may result in large PF errors especially in lean children.

Plasma concentration of organochlorine compounds is associated with age and not obesity

It has been suggested that obese individuals, because of an increased dilution space (body fat) for lipophilic organochlorines compounds, may have greater levels of toxic pollutants than lean sedentary individuals. It is important to further examine this possibility because of the potential contribution of organochlorine pesticides in the development of Parkinson's disease and other neurological diseases. The aim of this study was to further investigate the relationship between the magnitude of obesity and the plasma concentration of organochlorines for a wide range of BMI (with participants at steady state body weight). Fifty-three individuals were selected on the basis of their body mass index (BMI): lean controls (n=16; mean BMI 22.8+/-2.2 kg/m(2); mean age 38.8+/-9.4 years), obese individuals (n=19; mean BMI 33.4+/-3.0 kg/m(2); mean age 38.6+/-7.6 years) and morbidly obese individuals (n=18; mean BMI 49.3+/-6.5 kg/m(2); mean age 44.3+/-9.2 years). Blood samples were analyzed for organochlorine compounds. The relationship between the total plasma organochlorine concentration and BMI was tested using a multiple regression analysis. Age was included in the model. There was no relationship between the total plasma organochlorine concentration and BMI. Organochlorine concentrations, however, were correlated with age (BMI-adjusted R(2)=0.46; p<0.001). At steady state body weight, toxic pollutant concentrations are not associated to obesity but strongly correlate with age.

Gender differences in ambulatory blood pressure monitoring profile in obese, overweight and normal subjects

The incidence of obesity has increased enormously in the past several decades, and has been described as a modern epidemic. Obesity is a major factor contributing to hypertension. To the best of our knowledge, no study of ambulatory blood pressure monitoring (ABPM) comparing men with women in relation to body mass indexes (BMI) has been performed. From December 2002 to May 2006, we performed 24-h ABPM in 5950 subjects (3102 men and 2848 women), with a wide range of BMI (range 15.9-53.2 kg/m(2)). We defined obese subjects as those with BMI> or =30.0 kg/m(2), overweight subjects as those with BMI>25.0 and <30.0 kg/m(2), and normal subjects as those with BMI< or =25.0 kg/m(2). Data on 989 subjects (501 men and 488 women) aged from > or =18 to < or =69 years without antihypertensive treatment, atrial fibrillation or diabetes were included for analysis. We consistently found that obese men had the expected increased heart rate compared to normal and overweight men, whereas women (normal, overweight and obese) had similar HRs. In addition, normal and obese women had similar diastolic blood pressures (BP), as opposed to obese men, who had raised diastolic BP. These results may indicate that different pathogenetic mechanisms may be involved in the relationship between obesity and hypertension in men and women.

Gastric Sensorimotor Functions and Hormone Profile in Normal Weight, Overweight, and Obese People

Peptide YY (PYY) levels are reported to be decreased in obesity. The relation between gastric functions, satiation, and gut hormones in obesity is incompletely understood. The aim of this study was to compare gastric volumes, emptying, maximum tolerated volumes, postchallenge symptoms, and selected gut hormones in normal, overweight, or obese healthy volunteers. In 73 nonbulimic normal, overweight, or obese participants weighing less than 137 kg, we measured gastric emptying of solids and liquids by scintigraphy (gastric emptying half-time [GE t(1/2)]); gastric volumes by single-photon emission computed tomography; maximum tolerated volumes and symptoms by satiation test; and plasma leptin, ghrelin, insulin, glucagon-like peptide 1, and PYY levels. Groups were compared using 1-way analysis of covariance adjusted for sex. Univariate associations among measured responses were assessed using Spearman correlations. Multiple linear regression models, adjusting for weight and sex, assessed the independent ability of gastric functions and hormones to predict satiation volume. Obese and overweight subjects had significantly lower postprandial gastric volumes, higher fasting and postprandial insulin and leptin levels, and lower fasting ghrelin and lower postprandial reduction in ghrelin levels. PYY levels were not different in obese or overweight subjects compared with controls. The GE t(1/2) was correlated inversely with postprandial PYY; increased body weight was associated with faster GE t(1/2) of solids (r(s) = 0.33, P = .005) and liquids (r(s) = 0.24, P = .04). Postprandial changes in gastric volume and PYY were independent predictors of satiation (both P = .01). Overweight or obesity are associated with lower postprandial gastric volumes and normal PYY levels. Gastric emptying influences postprandial PYY levels. Postprandial PYY and gastric volume independently predict satiation volume in nonbulimic people across a wide body mass index range.

The relative impact of different measures of adiposity on markers of early atherosclerosis

Background Although there are several methods available to assess adiposity, there is still controversy on the relative clinical utility of each of these methods. This study examines the relative impact of different measures of adiposity on markers of early atherosclerosis. In particular weight changes over time have been poorly assessed in this setting. Methods Eighty-six healthy individuals (31 men, age 36.5 ± 8.9 years) with a wide range of body-mass index (28.7 ± 7.0, 18.9–57.9 kg/m 2) without hypertension, diabetes or smoking were examined. In addition to waist circumference and waist-to-hip ratio self-reported weight change since adolescence was also calculated. Ultrasonography was used to measure abdominal fat layers and their ratio. Flow-mediated dilatation of the brachial artery, serum levels of intercellular adhesion molecule (sICAM-1) and mean intima-media thickness of the carotid artery were measured as markers of early atherosclerosis. Results Stepwise multivariate regression analysis showed waist circumference and waist-to-hip ratio as the only independent predictor of flow-mediated dilatation. Waist circumference and weight change but not current body-mass index were independent predictors of intima-media thickness. These correlations were not influenced by ultrasonographically measured fat layers, C-reactive protein and basal insulin resistance. Body-mass index and weight gain were associated with sICAM-1 but not independently of basal insulin resistance and C-reactive protein. Conclusions Waist circumference and weight gain were the strongest predictors of early atherosclerosis in a population of apparently healthy adults. The ultrasonographically measured fat layers did not provide additional information in this population.

Is the association between physical activity and body mass index obesity dependent?

Most studies indicate an inverse relationship between physical activity (PA) and body mass index (BMI). However, the impact of obesity on this relationship is unclear. To scrutinize the BMI/PA relationship by analysing multiple categories of PA from a sample with a wide BMI range. PA was measured with accelerometry for 7 consecutive days during free-living conditions in 85 severely obese outpatients (mean BMI 42.7 kg/m(2) (s.d. 6.1); age 43.0 year (12.6)) and 193 control subjects (24.0 kg/m(2) (3.5); 41.6 year (13.0)). Six categories of PA were calculated from the accelerometer data (min/day of sedentary time, min/day of light PA, min/day of moderate PA, min/day of vigorous PA, activity counts/day and steps/day). Participants were stratified in obese and non-obese subgroups (BMI=30 kg/m(2) as cutoff). Associations between BMI and PA were examined in the total sample, and in subgroups. The impact of sex and age on the BMI/PA association was tested. In the total sample, the association between BMI and PA was significant in all PA categories except for time spent sedentary (P=0.68). However, in subgroup analyses, the association between BMI and PA in non-obese was only significant for activity counts/day (r=-0.16, P<0.05) and vigorous intensity PA (r=-0.15, P=0.05). After adjustment for age, vigorous PA remained significantly associated with BMI in the non-obese (r=-0.17, P<0.05). In obese individuals, significant associations between BMI and PA were found for all six PA categories (age adjusted), sedentary time (r=0.26, P=0.05), light PA (r=-0.30, P<0.01), moderate PA (r=-0.35, P<0.01), vigorous PA (r=-0.39, P<0.001), activity counts/day (r=-0.50, P<0.001) and steps/day (r=-0.54, P<0.001). The association between PA and BMI was weak in non-obese individuals. In contrast, BMI was highly significantly associated with PA in obese individuals. Longitudinal studies are needed to tease out the direction of association between PA and BMI across BMI categories, as the cross-sectional associations seem to be dependent on obesity status.

Validation of three predictive equations for basal metabolic rate in adults

To cross-validate three predictive set of equations for basal metabolic rate (BMR) developed by Schofield (Schofield database), Henry (Oxford database) and Cole (Oxford database) using mean values for age, weight, height and BMR of published studies. Literature review of studies published from 1985 to March 2002. All studies selected used appropriate methods and followed conditions that met the criteria established for basal metabolism, were performed in healthy adults, and were not part of the Schofield or Oxford database. A total of 261 groups of men and women from 175 studies were selected and categorised in three age groups (18.5-29.9, 30.0-59.9, > or = 60 years old) and three body mass index (BMI) groups (normal weight, overweight and obese). Linear regression and concordance correlation analysis showed that the three sets of equations had the same association and agreement with measured BMR, across gender, age, and BMI groups. The agreement of all equations was moderate for men and poor for women. The lowest mean squared prediction errors (MSPRs) were given by Henry equations in men and Cole equations in women. Henry and Cole equations gave lower values than Schofield equations, except for men over 60 years of age. Henry equations were the most accurate in men. None of the three equations performed consistently better in women. These results support the use of Henry equations in men with a wide range of age and BMI. None of the proposed predictive equations seem to be appropriate to estimate BMR in women.

Correlation of apolipoprotein M with leptin and cholesterol in normal and obese subjects

Apolipoprotein M (apoM) is a recently characterized apolipoprotein that is exclusively expressed in the liver and kidney. In plasma it is present predominantly in high-density lipoprotein (HDL). The physiological function of apoM is not yet known. In the present study we investigated relationships between plasma apoM levels and leptin levels, body mass index (BMI), as well as fasting glucose and other lipid parameters in women with a wide range of BMI (18.9–57.1 kg/m 2, n = 51). In univariate analysis, apoM correlated significantly with leptin ( r = 0.54, P < 0.001), BMI ( r = 0,70, P < 0.001), fasting insulin ( r = 0.33, P = 0.025), total cholesterol ( r = −0.41, P = 0.016), and LDL-cholesterol ( r = −0.39, P = 0.018). The correlations between apoM and cholesterol and between apoM and leptin remained significant after adjustment for the influence of BMI. Forward stepwise multiple regressions when leptin, BMI, insulin, and cholesterol were entered into a model as independent variables and apoM as the dependent variable, showed that cholesterol and leptin were independent predictors of circulating apoM. These two parameters yielded a value of r 2 = 0.28, thereby explaining approximately 30% of the variance in apoM. Hence, we show that apoM is positively related to leptin and negatively related to cholesterol in humans.

Body water distribution in severe obesity and its assessment from eight-polar bioelectrical impedance analysis.

To measure body water distribution and to evaluate the accuracy of eight-polar bioelectrical impedance analysis (BIA) for the assessment of total body water (TBW) and extracellular water (ECW) in severe obesity. Cross-sectional study. Obesity clinic. In all, 75 women aged 18-66 y, 25 with body mass index (BMI) between 19.1 and 29.9 kg/m(2) (ie not obese), 25 with BMI between 30.0 and 39.9 kg/m(2) (ie class I and II obese), and 25 with BMI between 40.0 and 48.2 kg/m(2) (ie class III obese). TBW and ECW were measured by (2)H(2)O and Br dilution. Body resistance (R) was obtained by summing the resistances of arms, trunk and legs as measured by eight-polar BIA (InBody 3.0, Biospace, Seoul, Korea). The resistance index at a frequency of x kHz (RI(x)) was calculated as height (2)/R(x). ECW : TBW was similar in women with class III (46+/-3%, mean+/-s.d.) and class I-II obesity (45+/-3%) but higher than in nonobese women (39+/-3%, P<0.05). In a random subsample of 37 subjects, RI(500) explained 82% of TBW variance (P<0.0001) and cross-validation of the obtained algorithm in the remaining 38 subjects gave a percent root mean square error (RMSE%) of 5% and a pure error (PE) of 2.1 l. In the same subjects, RI(5) explained 87% of ECW variance (P<0.0001) and cross-validation of the obtained algorithm gave a RMSE% of 8% and a PE of 1.4 l. The contribution of weight and BMI to the prediction of TBW and ECW was nil or negligible on practical grounds. ECW : TBW is similar in women with class I-II and class III obesity up to BMI values of 48.2 kg/m(2). Eight-polar BIA offers accurate estimates of TBW and ECW in women with a wide range of BMI (19.1-48.2 kg/m(2)) without the need of population-specific formulae.

Waist circumference, waist-to-hip ratio and body mass index as predictors of adipose tissue compartments in men

The accumulation of fat in visceral and posterior subcutaneous adipose tissue compartments is highly correlated with the metabolic abnormalities that contribute to increased risk of diabetes mellitus and cardiovascular disease. To determine which of waist circumference (WC), waist-to-hip ratio (WHR) and body mass index (BMI) was the best predictor of intraperitoneal and posterior subcutaneous abdominal adipose tissue mass in men. We studied 59 free-living men with a wide range of BMI. WC, WHR and BMI were determined using standard methods. Intraperitoneal, retroperitoneal, anterior subcutaneous and posterior subcutaneous abdominal adipose tissue masses (IPATM, RPATM, ASAATM and PSAATM, respectively) were quantified using magnetic resonance imaging. In univariate regression analysis, WC, WHR and BMI were all significantly and positively correlated (all p < 0.05) with IPATM, RPATM, ASAATM and PSAATM. To assess the relative strength of these associations, we used non-nested regression models. There was no significant difference between WC and WHR in predicting IPATM and RPATM; WC was a stronger predictor of ASAATM (p < 0.001) and PSAATM (p < 0.001) than WHR; WC was also a stronger predictor of IPATM (p = 0.042) and RPATM (p = 0.045) than BMI, but the relative strengths of WC and BMI in predicting ASSATM and PSAATM did not different significantly (p > 0.05); there was no significant difference between BMI and WHR in predicting IPATM and RPATM (p>0.05), but BMI was a stronger predictor of ASAATM (p = 0.036) and PSAATM (p < 0.001) than WHR. In men WC is the anthropometric index that most uniformly predicts the distribution of adipose tissue among several fat compartments in the abdominal region, there apparently being little value in measuring WHR or BMI.

Interpretation of circulating C-reactive protein levels in adults: Body Mass Index and gender are a must

The recently demonstrated association between C-reactive protein (CRP) level and body mass index (BMI) raised the question of the link between CRP and the degree of obesity. In the present study, we measured CRP in a healthy population with a wide range of BMI in order to appreciate the influence of overweight in the interpretation of CRP results in clinical use. Blood donors, aged from 19 to 65 years, were included in the study. According to BMI, subjects were classified into 3 groups: A (BMI<25 kg/m(2), n=611); B (25-30, n=147); C (> 30, n=34). CRP values were different among women and men. CRP progressively increased with BMI in women. These results clearly showed that average level of CRP was quite different according to BMI and gender of the subjects and generated different normal ranges of CRP expressed in mg/L (median, 75(th) percentile): Group A: women: 0.44, 0.93; men: 0.40, 0.79, Group B: women: 1.28, 1.84; men: 0.84, 2.17, Group C: women: 3.61, 7.21; men: 1.16, 3.08. Our results suggest that for an inflammatory disease diagnosis, a CRP concentration of 5 mg/L is normal for obese women but is five times the 75(th) percentile for normal people.

Blood pressure in relation to relative weight at birth through childhood and youth in obese and non-obese adult men.

To determine the influence on blood pressure of relative weight from birth through adulthood in non-obese and juvenile obese men. Case-cohort study of obesity in Danish men, identified at age (mean+/-s.d.) 19.8+/-1.6 y at draft board examination, who participated in at least one of two follow-up studies in adulthood (age 36.8+/-6.7 and 47.9+/-6.8 y at first and second follow-up, respectively). Birth weight and weight and height from the age of 7-13 y were collected from school health records. Three hundred and twenty-seven non-obese men (controls) selected as 0.5% of the draft board population and 285 obese men with body mass index (BMI)> or =31 kg/m(2) at draft board examination. Systolic and diastolic blood pressure measured twice in adulthood adjusted for current age. Birth weight was inversely related to systolic blood pressure at first and second follow-up, but only significantly so when adjusted for current BMI (regression coefficients in mmHg per unit Z-score (95% confidence interval (CI))-1.2 (-2.3, -0.1) and -1.6 (-3.1, 0.0)). Change in Z-score from birth weight to BMI at the age of 7 y was significantly positively related to systolic blood pressure, but the relationship weakened by adjustment for current BMI (0.8 (0.1, 1.6) and 0.6 (-0.4, 1.6), respectively). If both birth weight and change until 7 y were included in the same model, their effects were both positive and significant, but they weakened and became not significant when adjusted for current BMI. BMI since the age of 7 y had no significant effect on blood pressure beyond that of current BMI. In a wide range of adult BMI in men, the birth weight was inversely related to systolic blood pressure, even when controlled for BMI since the age of 7 y. However, the effect may reflect the weight change between birth and 7 y of age. After that age BMI had no additional effect on blood pressure beyond the effect of current BMI.

WHO and ADA criteria for the diagnosis of diabetes mellitus in relation to body mass index. Insulin sensitivity and secretion in resulting subcategories of glucose tolerance.

To determine the influence of body mass index (BMI) on agreement between the American Diabetes Association (ADA) and the new World Health Organization diagnostic criteria for the diagnosis of diabetes mellitus and to investigate the metabolic profile of the resulting subcategories. Cross-sectional study A total of 3018 subjects with no previous history of diabetes and fasting glucose <7.8 mmol/l, with a wide range of BMIs. (1) Prevalence of impaired glucose regulation (IGR) and diabetes (DM) according to ADA and WHO diagnostic criteria; (2) basal and post-load insulin sensitivity and secretion, calculated on the basis of data derived from an oral glucose tolerance test (OGTT). The diagnosis according to the two classifications was concordant in 2490 subjects, discordant in 528 (452 were identified as impaired glucose tolerance (IGT) and 76 as DM only by means of OGTT). The disagreement increased with increasing BMI, being as high as 25.3% in subjects with BMI > or = 35 kg/m(2). Subjects with isolated fasting hyperglycaemia were mainly characterised by reduced insulin sensitivity and secretion in the basal state, but normal first-phase insulin secretion and moderately reduced insulin sensitivity after glucose challenge. Subjects with isolated 2 h hyperglycaemia were mainly characterised by normal basal insulin secretion and by a marked insulin resistance associated with a blunted first-phase insulin secretion after the glucose load. The disagreement between ADA and WHO classifications is particularly relevant in obesity, making OGTT mandatory in these subjects. Different pathogenic mechanisms are involved in isolated fasting or post-load hyperglycaemia, possibly related to a different site of insulin resistance (hepatic vs peripheral), and/or to a different disregulation of insulin secretion (basal vs post-load). A correct identification of the underlying mechanism(s) is the rationale for future studies to detect the effectiveness of different pharmacological or behavioural approaches.

Leptin and Aging: Correlation with Endocrine Changes in Male and Female Healthy Adult Populations of Different Body Weights

Aging is associated with changes in plasma levels of several hormones. There are conflicting reports on whether circulating leptin levels change during aging, the possible explanation for which is that alterations in adiposity and body mass index (BMI) also occur. In this study we measured plasma leptin and other hormonal parameters known to influence leptin in 150 men and 320 women of a wide age (18-77 yr) and BMI (18.5-61.1 kg/m2) range. Subjects of each gender were separated into 2 groups of similar BMI, i.e. nonobese (BMI, <30) and obese (BMI, >30), and treated separately. Statistical analysis was performed, treating each group of subjects as a whole population or divided into age groups (<30, 30-50, and >50 yr). BMI-adjusted leptin levels were progressively lower with increasing age in women, with a consistent fall after menopause (-21%; P < 0.001); in men, leptin levels also tended to be lower in subjects more than 50 yr of age, but the reduction was not significant. Multiple linear regression analysis, performed on subjects treated either as a whole population or divided into obese and nonobese, showed that in both genders BMI and age were independent contributors of leptin levels, and there was an inverse relationship between leptin and age in both obese (standardized coefficient beta = -0.25 in women and -0.23 in men; P < 0.01) and nonobese (-0.22 in women and -0.20 in men; P < 0.05) subjects. The correlation of leptin and age with plasma levels of sex and thyroid hormones, GH, insulin-like growth factor I, PRL, and insulin was also evaluated. The variables that correlated with leptin were included in a multiple regression model that included BMI and age. Testosterone in men (-0.43 in nonobese and -0.19 in obese; P < 0.05) and estradiol in women (0.22 in nonobese and 0.24 in obese; P < 0.05) were important contributors to leptin levels; also, dehydroepiandrosterone sulfate in obese women (-0.16) and sex hormone-binding globulin in obese subjects of both genders (0.15 in women and 0.19 in men) were significant determinants in the model. However, none of the hormonal parameters abolished the negative correlation between leptin and age or the gender difference in leptin levels. In conclusion, our data show that in adult humans of different body weight, serum leptin gradually declines during aging; leptin reduction is higher in women than in men, but it is independent from BMI and other age-related endocrine changes.