Prediction and evaluation of resting energy expenditure in a large group of obese outpatients.

BACKGROUND/OBJECTIVES: The aim of this study was to compare resting energy expenditure (REE) measured (MREE) by indirect calorimetry (IC) and REE predicted (PREE) from established predictive equations in a large sample of obese Caucasian adults. SUBJECTS/METHODS: We evaluated 1851 obese patients (body mass index (BMI)>30 kg m-2) aged between 18a and 65 years. Data were obtained by comparing MREE with PREE, derived from different equations, within and between normal weight and obese groups. The mean differences between PREE and MREE as well as the accuracy prediction within ±10% level were investigated in the whole sample and in three subgroups, classified by BMI (Group 1=30-39.9 kg m-2; Group 2=40-49.9 kg m-2; Group 3>50 kg m-2). RESULTS: We observed that FAO, Henry and Muller3 (body composition (BC)) equations provided good mean PREE-MREE (bias -0.7, -0.3 and 0.9%; root mean standard error (RMSE) 273, 263 and 269 kcal per day, respectively); HB and Henry equations were more accurate individually (57 and 56.9%). Only the Muller1 (BC) equation gave the lowest PREE-MREE difference (bias -1.7%; RMSE 228 kcal per day) in females, while Johnstone and De Lorenzo equations were the most accurate (55.1 and 54.8%). When the sample was split into three subgroups according to BMI, no differences were found in males; however, the majority of the equations included in this study failed to estimate REE in severely obese females (BMI>40 kg m-2). Overall, prediction accuracy was low (~55%) for all predictive equations, regardless of BMI. CONCLUSIONS: Different established equations can be used for estimating REE at the population level in both sexes. However, the accuracy was very low for all predictive equations used, particularly among females and when BMI was high, limiting their use in clinical practice. Our findings suggest that the validation of new predictive equations would improve the accuracy of REE prediction, especially for severely obese subjects (BMI>40 kg m-2).

Iron absorption following a single oral dose of ferrous sulfate or ferric gluconate in patients with gastrectomy.

BACKGROUND: Iron deficiency anemia frequently occurs in gastrectomized patients. METHODS: Serum iron levels following the ingestion of a single oral dose of 105 mg elemental iron, taken as ferrous sulfate (FeS) or ferric gluconate (FeG), have been evaluated in 20 gastrectomized patients (and 20 controls). All subjects participated on 2 different test days, 1 month apart: they took a single dose of 105 mg elemental iron as FeS or FeG after a night of fasting. Serum iron concentrations at baseline, 30, 60, 120 and 180 min after the oral dose administration were measured. RESULTS: In patients and controls receiving FeG, serum iron levels did not significantly change. After oral ingestion of FeS, patients' serum iron levels gradually increased. The increase in serum iron levels was 148 and 168% at 120 and 180 min in patients (p < 0.0001 for both evaluations), whilst in controls, it was 216% at 120 min and 234% at 180 min, i.e. significantly higher than in gastrectomized patients (p < 0.001 for both evaluations). CONCLUSIONS: In gastrectomized patients, a single oral dose of FeS shows a significant increase in iron serum concentration, albeit lower than in controls. Further studies on a larger sample of patients will be necessary to confirm these results.

The absence of polymorphisms in ADRB3, UCP1, PPARγ, and ADIPOQ genes protects morbid obese patients toward insulin resistance.

BACKGROUND AND AIMS: The insulin resistance (IR) is a major metabolic impairment in severe obesity, a multifactorial disease in which the importance of the effect of single nucleotide polymorphisms (SNP) associations in different rather than individual genes was established. The aim of this study was to test the predictive value of presence/absence of polymorphisms/ variants in ß3-adrenergic receptor (ADRB3), uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor γ (PPARγ), and adiponectin (ADIPOQ) genes in diagnosing the IR in obesity. SUBJECTS AND METHODS: We studied 112 (40 males, 72 females) severely obese (body mass index: 48.5±7.5 kg/m2) subjects recruited from the outpatient obesity clinic of Federico II University Hospital in Naples. Genomic DNA was extracted from peripheral leukocytes with a commercial kit. The gene polymorphisms Trp64Arg in ADRB3, -3826 A>G in UCP1, Pro12Ala in PPARγ, and c.268G>A, c.331T>C, and c.334C>T in ADIPOQ were characterized by TaqMan assay or by direct sequencing (ADIPOQ). RESULTS AND CONCLUSION: Our results demonstrate that -3826A>G UCP1 polymorphism is associated with IR in morbid obesity. Further, the lack of any polymorphisms, Trp64Arg in ADRB3 and/or -3826 A>G in UCP1 and/or Pro12Ala in PPARγ and/or c.268G>A, c.331T>C and c.334C>T in ADIPOQ, appears a useful prognostic factor (NPV=100%) toward the IR onset in these obese patients representing a further parameter for an earlier and appropriate therapy.

Circulating levels of cytochrome C, gamma-glutamyl transferase, triglycerides and unconjugated bilirubin in overweight/obese patients with non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease, characterized by hepatocyte apoptosis, is distinct in fatty liver and non-alcoholic steatohepatitis, the more severe form. Apoptotic cell death is caspase-dependent and associated with mitochondrial membrane depolarization and cytochrome c release. Adhering to the hypothesis that the exposure of hepatocytes to free fatty acids, resulting in increased ROS production and mitochondrial damage, is balanced by the presence of antioxidant substances, circulating levels of gamma-glutamyl transferase, cytochrome c, triglycerides and unconjugated bilirubin were explored in patients suffering from non-alcoholic fatty liver disease with different severity. One hundred and eighty-six consecutive patients who presented recent ultrasound feature of bright liver without any liver disease of known origin were enrolled, eighty-nine of whom underwent liver biopsy. Forty-five subjects were allocated on the basis of histology in fatty liver group while 44 patients formed the group with non-alcoholic steatohepatitis. A cohort of 27 young, lean, apparently healthy individuals was selected as control group. The levels of gamma-glutamyl transferase were normal or slightly increased, while unconjugated bilirubin concentrations were elevated in all the spectra of non-alcoholic fatty liver disease. Comparing the present results with relevant findings from other studies dealing with diseases characterized by apoptosis, we did not find high circulating levels of cytochrome c in non-alcoholic fatty liver disease. What is more, our patients, categorized as suffering from simple fatty liver or from the more severe non-alcoholic steatohepatitis, had similar levels of cytochrome c and gamma-glutamyl transferase, p=0.19 and 0.11. Serum triglycerides were higher in patients with non-alcoholic fatty liver disease than in the healthy group, p=0.001. These findings likely reflect a balance between oxidative stress and anti-oxidant response rather than a lack of reliability of cytochrome c as a reliable biomarker of mitochondrial damage.

[Obesity and Eating Disorders. Indications for the different levels of care. An Italian Expert Consensus Document]. / Documento di Consensus. Obesità e Disturbi dell'Alimentazione Indicazioni per i diversi livelli di trattamento.

This paper is an Italian Expert Consensus Document on multidimensional treatment of obesity and eating disorders. The Document is based on a wide survey of expert opinion. It presents, in particular, considerations regarding how clinicians go about choosing the most appropriate site of treatment for a given patient suffering from obesity and/or eating disorders: outpatient, partial hospitalization, residential rehabilitation centre, inpatient hospitalization. In a majority of instances obesity and eating disorders are long-term diseases and require a multiprofessional team-approach. In determining an initial level of care or a change to a different level of care, it is essential to consider together the overall physical condition, medical complications, disabilities, psychiatric comorbidity, psychology, behaviour, family, social resources, environment, and available services. We first created a review manuscript, a skeleton algorithm and two rating scales, based on the published guidelines and the existing research literature. As the second point we highlighted a number of clinical questions that had to be addressed in the specific context of our National Health Service and available specialized care units. Then we submitted eleven progressive revisions of the Document to the experts up to the final synthesis that was approved by the group. Of course, from point to point, some of the individual experts would differ with the consensus view. The document can be viewed as an expert consultation and the clinical judgement must always be tailored to the particular needs of each clinical situation. We will continue to revise the Document periodically based on new research information and on reassessment of expert opinion to keep it up-to-date. The Document was not financially sponsored.

UCP1 -3826 AG+GG genotypes, adiponectin, and leptin/adiponectin ratio in severe obesity.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MS) are well-recognized complications of obesity. This study was designed to evaluate the role of the UCP1 -3826 A>G polymorphism, adiponectin levels, leptin/adiponectin ratio (L/A), and main biochemical parameters in 102 unrelated severely obese adults [61 females and 41 males, median body mass index (BMI) = 47.8 kg/m2] with NAFLD, with (MS+) or without MS (MS-) from Southern Italy. SUBJECT AND METHODS: The UCP1 polymorphism was tested by the TaqMan method, main biochemical parameters by routinary methods, adiponectin, and leptin serum levels by enzyme-linked immunosorbent assay. MS was diagnosed according to the American Heart Association criteria, liver steatosis was detected by ultrasound. RESULTS: MS was present in 53% male and 66% female obese patients. Only total cholesterol (p=0.04 males and p=0.002 females) and L/A ratio (p=0.03 males) differed between MS+ and MS- obese patients. At multivariate analysis, severe liver steatosis was significantly associated with: UCP1 (AG+GG) genotypes [odds ratio-confidence interval (OR-CI): 4.25; 1.12-16.13], MS (OR-CI: 8.47; 1.78-40.25), low adiponectin levels (OR-CI: 0.92; 0.87-0.98), high alanine aminotransferase levels (OR-CI: 1.03; 1.00-1.06), age (ORCI: 1.08; 1.00-1.15), and male gender (OR-CI: 10.78; 1.61- 71.96). CONCLUSION: In addition to traditional factors, total cholesterol and L/A ratio appear to contribute to MS characterization in severe obesity. Furthermore, the UCP1 (AG+GG) genotypes and low adiponectin levels could predispose to a more severe liver steatosis independently of MS presence. Based on our data, polymorphic UCP1 (AG+GG) obese patients with low adiponectin levels appear to be high-risk subjects for worsening of liver steatosis, a NAFLD, possibly requiring a second-step evaluation by liver biopsy.

Molecular analysis of the adiponectin gene in severely obese patients from southern Italy.

BACKGROUND: Severe obesity is a major worldwide public health concern affecting 0.5-5% of the adult population. Adiponectin (Acpr30), an adipokine secreted from adipocytes, shows pleiotropic beneficial effects on obesity and related disorders. In this study, sequence analysis of Acpr30 gene (ACDC) was performed in a highly selected population of severely obese young adult patients from Southern Italy to investigate the associations between polymorphisms in the ACDC gene and the development of severe obesity concomitantly with other features of the metabolic syndrome. METHODS: The ACDC gene was analyzed by direct sequencing in the severely obese patients (n=220) and compared to healthy controls (n=116). The associations between the ACDC gene single-nucleotide polymorphisms (SNPs) and the levels of serum Acpr30 as well as the correlation with the presence of severe obesity jointly associated with other features of the metabolic syndrome were also investigated. Total serum Acpr30 concentrations were measured by the ELISA method. RESULTS: ACDC gene molecular screening revealed the presence of previously described SNPs and a new nucleotide alteration, c.355T>G, leading to a protein variant, p.L119V. Measurement of serum concentration of Acpr30 demonstrated lower levels of Acpr30 in the obese population compared to controls (30.5+/-28.3 vs. 43.9+/-35.7 microg/ml, p<0.01); in particular, significantly lower Acpr30 concentrations were observed in obese patients bearing c.-11377C>G SNP CG+GG genotypes than in those with CC genotype (22.9+/-20.5 vs. 33.1+/-29.4 microg/ml, p<0.05). CONCLUSIONS: Our results confirmed that low serum levels of Acpr30 are related to severe obesity and a difference in protein expression is associated with variants in ACDC gene promoter region.

Prevalence of home artificial nutrition in Italy in 2005: a survey by the Italian Society for Parenteral and Enteral Nutrition (SINPE).

AIM: To determine the prevalence (cases per million inhabitants) of home artificial nutrition (HAN), enteral (HEN) and parenteral (HPN), in Italy, grouped according to administrative regions, patient age and primary disease, and to analyze the impact both of the presence of an HAN regional regulation and of demographic characteristics. METHODS: In April 2005, the Regional Coordinators of the Italian Society for Parenteral and Enteral Nutrition (SINPE) recorded all the ongoing cases of HAN using a structured questionnaire and were asked to estimate the representativeness of the collected sample with respect to the total expected HAN. RESULTS: A total of 6955 cases of HAN (93.5% adults, 6.5% pediatric patients < or = 18 years) were recorded in 16 of the 20 Italian regions (80% of the Italian population; sample representativeness 78%). HAN prevalence 152.6 (83.9% HEN, 16.1% HPN); the HAN range among the regions was: prevalence 28.1-519.8; oncological disease 13.8-75.7%, neurological disease 15.5-79.9%, intestinal failure 1.3-14.0%. An HAN regulation was present in 11 regions. A positive association (P=0.012) was found between the number of years since the regulation was issued and the HAN prevalence, and also between the % neurological patients and the population density (P=0.130) and the % inhabitants > or = 75 years (P=0.040). CONCLUSIONS: The need for HAN regards a great number of patients throughout the country; there are substantial differences between the regions with respect to both the prevalence and the use of HAN in various disease categories. A specific regulation may favor the development of HAN.

Long-term mortality in anorexia nervosa: a report after an 8-year follow-up and a review of the most recent literature.

OBJECTIVE: To evaluate long-term mortality rate of anorexia nervosa (AN) patients in a southern Italy population compared to the most recent literature. DESIGN: Retrospective and review setting. PATIENTS AND INTERVENTIONS: One hundred and forty-seven female AN patients, consecutively admitted from 1994 to 1997 to the Outpatient Unit, were re-examined between June and November 2003. Our data are compared with 10 other studies published since 1988. RESULTS: One hundred and twenty-three deaths in 2240 patients, amounting to a total mortality rate of 5.25% were reported in the literature. Deaths due to suicide, AN-related and AN-unrelated diseases were 1.20, 3.07 and 0.98%, respectively. After correcting for unrelated deaths, mortality rate was 4.27%. In our 8-year follow-up, we found a mortality rate of 2.72% (1.82% after correcting for unrelated deaths). Standardized mortality ratio was 9.7. CONCLUSION: We interpret our favourable findings as a consequence of an integrated, clinical-nutritional and psychiatric approach. Finally, considering AN demographic characteristics, that is young female subjects in Westernized societies, mortality rate is confirmed to be dramatically high.

Metabolic syndrome and ADRB3 gene polymorphism in severely obese patients from South Italy.

OBJECTIVE: To evaluate the prevalence of beta(3)-adrenergic receptor (ADRB3) Trp64Arg polymorphism and its relationship with the metabolic syndrome in severe obesity. DESIGN: Cross-sectional outpatients study. PATIENTS AND METHODS: In 265 (100 men) severely obese non-diabetic subjects and 78 (25 men) healthy volunteers, genomic DNA was isolated from peripheral leukocytes. In obese patients, plasma concentrations of leptin, lipids, glucose and insulin, the homeostasis model assessment index and blood pressure have been measured. The Trp64Arg mutation was identified with the real-time TaqMan method. RESULTS: Neither genotype distribution nor allele frequency differed between the two groups. The metabolic syndrome prevalence was 59% in obese subjects, and was higher in men than in women (65 vs 55%: P=0.03). The body mass index (BMI) was related to age tertiles (beta=0.08; P<0.001; multiple linear regression) in Trp64Arg-positive obese subjects. CONCLUSION: We confirm the high prevalence of the metabolic syndrome among severely obese subjects. ADRB3 polymorphism was significantly related to insulin resistance only in obese male subjects. Moreover, increased BMI was related to age in obese subjects with the ADRB3 polymorphism.

Adult home parenteral nutrition: a clinical evaluation after a 3-year experience in a Southern European centre.

AIM: To evaluate the current use of Home Parenteral Nutrition (HPN) in a Southern European region. SUBJECTS AND METHODS: A total of 159 (86 m, 73 f) HPN patients, mean age 60.1 +/- 14.2 years, BMI 18.8 +/- 3.3kg/m2, consecutively referred to the Artificial Nutrition outpatient Unit of the Federico II University Hospital in Naples (Italy), from January 2000 to December 2002 and treated for at least 4 weeks. Retrospective evaluation of baseline disease, indications and duration of HPN treatment, type of venous access, complications. RESULTS: In all, 140 (88%) were cancer and 19 (12%) noncancer patients. Main indications were carcinosis in 68 for total, and hypophagia/dysphagia in 62 patients for partial/integrative (to oral-enteral nutrition) HPN; mean duration of HPN was 81.45 +/- 110.86 days of treatment and infection rate 2.89% in the whole population and 2.66% in the 36 patients treated for more than 3 months. No other major complications have been observed. CONCLUSION: HPN is confirmed to be a safe and effective treatment when prescribed and administered by a trained team.

Hematological complications in anorexia nervosa.

BACKGROUND/OBJECTIVES: Anemia, leukopenia and, although less frequently, thrombocytopenia are possible hematological complications of anorexia nervosa considered strictly secondary to chronic malnutrition. This is a retrospective study on the prevalence of these disorders in a large cohort of 318 female patients with AN (20.4±5.6 years, body mass index (BMI) 15.9±1.6 kg/m2), recruited in the Outpatient Unit for Malnutrition secondary to Eating Disorders at the Department of Clinical Medicine and Surgery, Federico II University Hospital, since February 1991 to December 2012. SUBJECTS/METHODS: Patients were studied on an outpatient basis after obtaining medical history, clinical examination, routine hematobiochemical and endocrine tests, electrocardiography, psychiatric interview and bioelectrical impedance analysis and, in particular, phase angle determination. All patients with other comorbidities, in particular with mean corpuscular volume <80 fl, were excluded for suspected genetic alteration in the synthesis of hemoglobin. RESULTS: Hematologic data showed that 16.7% of patients had anemia, 7.9% neutropenia and 8.9% thrombocytopenia. These abnormalities were strictly related to the duration of illness (P=0.028), and to protein energy malnutrition, in particular, BMI and phase angle (P<0.001). CONCLUSIONS: Our study offers description of the incidence of hematologic defects in a selected and large sample of AN female patients, suggesting that its incidence is related to the degree and duration of protein energy malnutrition.

Relation of left ventricular diastolic properties to systolic function in arterial hypertension.

BACKGROUND: It is unclear whether impairment of left ventricular (LV) diastolic characteristics is independent of systolic dysfunction. METHODS AND RESULTS: To address this issue, 159 consecutive hypertensive patients (44+/-11 years, 78 obese, 96 women) and 165 normotensive subjects (32+/-11 years, 84 obese, 110 women) were studied with the use of Doppler echocardiography. After adjustment for age, body mass index (BMI), and sex, we found that ejection fraction (EF; M-mode, z-derived) was higher in hypertensive (66. 6+/-5.2%) than in normotensive (63.9+/-4.4%, P<0.0001) subjects, whereas midwall shortening (MS) was lower (hypertensive patients 16. 9+/-2.0%, normotensive subjects 17.8+/-2.2%, P<0.02), even after correction for end-systolic wall stress (P<0.05). Isovolumic relaxation time (IVRT) was greater in hypertensive patients (103+/-14 ms) than in normotensive subjects (78+/-19 ms), as was deceleration time of E velocity and peak A velocity (all P<0.0001). In multivariate analysis, IVRT was unrelated to EF, but a negative relation was found with MS (P<0.001), independent of age, BMI, presence of arterial hypertension, LV geometry, and load (multiple R(2)=0.58). For comparable age, sex distribution, BMI, and blood pressure values, hypertensive patients with lower afterload-adjusted MS exhibited longer IVRT than patients with normal MS (P<0.005). However, IVRT remained higher than in normotensive control subjects after control for LV geometry and load. CONCLUSIONS: Doppler indices of delayed LV relaxation can be detected in the presence of normal or supranormal EF but are independently related to impaired MS. A less severely abnormal relaxation, however, can be also detected in the presence of normal midwall function, independent of LV geometry and load. Thus, diastolic abnormalities may occur before systolic dysfunction even when it is measured at the midwall.

Left ventricular filling in arterial hypertension. Influence of obesity and hemodynamic and structural confounders.

We assessed the relations of left ventricular filling to load and geometry by Doppler echocardiography in 80 normotensive subjects (40 normal-weight [36 +/- 12 years, 24 women] and 40 obese [35 +/- 13 years, 24 women]) and 61 hypertensive subjects without silent coronary heart disease (29 normal-weight [43 +/- 13 years, 15 women] and 32 obese [42 +/- 13 years, 19 women]) and comparable left ventricular midwall performance. Left ventricular mass divided by height to the 2.7 power was higher in all groups than in normotensive normal-weight subjects (all P < .0001) and in hypertensive than normotensive obese subjects (P < .001). After controlling for age, sex, blood pressure, and heart rate, isovolumic relaxation time was prolonged in hypertensive subjects and normotensive obese subjects compared with normotensive normal-weight subjects (all P < .0001). Body mass index, left ventricular dimension and mass, and circumferential end-systolic stress did not influence these differences. In pooled groups, prolonged isovolumic relaxation time was predicted by high mean blood pressure (beta = 0.52, P < .001), low end-systolic stress (beta = -0.33, P < .001), increased left ventricular mass (beta = 0.24, P < .004), and high body mass index (beta = 0.14, P < .05, multiple R = .72, SEE = 16.5 milliseconds, P < .0001). Between-group differences in peak early transmitral flow velocity, the deceleration time of early filling velocity, and the ratio of early to late left ventricular filling disappeared after controlling for left ventricular mass. Thus, (1) isovolumic relaxation time is prolonged in both arterial hypertension and obesity; (2) the presence of obesity does not significantly increase isovolumic relaxation time in hypertension; and (3) abnormalities of left ventricular filling in arterial hypertension are offset after controlling for left ventricular mass.

Relations of left ventricular geometry and function to body composition in children with high casual blood pressure.

To determine whether abnormal casual blood pressure (BP) is associated with left ventricular (LV) abnormalities in children, 190 6- to 11-year-old children (77 girls, 113 boys) were studied at a school site in Naples, Italy, by limited echocardiography and bioelectric impedance to calculate fat-free body mass (FFM). Single-visit BP measurements (defined as casual BP) were high (based on the Italian tables of BP) in 34 children (18%; 9 girls, 25 boys; 133+/-8/81+/-10 mm Hg) and obesity was present in 44 (23%; 15 girls, 29 boys). Sex- and age-independent risk of high casual BP value was 2.9-fold (odds ratio) greater in obese than in normal-weight children (95% confidence interval, 1.3 to 6.5; P<.01). LV mass (as both absolute value and normalized for height or FFM) was higher and relative wall thickness increased in children with high casual BP (all P<.01). Prevalence of LV hypertrophy was 21% among children with high casual BP (P<.004 versus 4.3% in normal group). Risk of LV hypertrophy was 5.5-fold higher in the presence of high casual BP (P<.004), whereas obesity, age, and sex did not have independent effects. Endocardial shortening was slightly higher in children with high casual BP (36.8+/-8.2%) than in children with normal BP (34.3+/-4.8%, P<.02), whereas midwall shortening was identical in the two groups (20%). Both endocardial shortening and midwall shortening were negatively related to end-systolic stress (r=-.62, SEE=3.8% and r=-.32, SEE=2.4% in normal children). Shortening as a percentage of predicted from wall stress was increased in children with high casual BP at the endocardial level (P<.001), whereas it was normal at the midwall. Therefore, (1) casual detection of high BP in school children is associated with LV geometric abnormalities similar to those found in adults with sustained hypertension (LV hypertrophy, concentric pattern); (2) similar to in adult hypertension, endocardial chamber function in children is supranormal; and (3) in contrast to findings in adults, midwall shortening is normal in children with high casual BP.

Interaction between body size and cardiac workload: influence on left ventricular mass during body growth and adulthood.

The development of the left ventricle parallels body growth. During infancy, the relation between body size and left ventricular (LV) mass is very close. With advancing age, variability of LV mass in relation to body size markedly increases. To test the hypothesis that the age-related increase in variability of LV mass is due to the progressive impact of hemodynamic stimuli on LV growth, quantitative M-mode echocardiograms were obtained in 766 normal-weight, normotensive individuals over a range of ages from 1 day to 85 years (330 female subjects, 373 subjects younger than 18 years). LV mass was linearly related to height2.7 (r2=.69). Prediction of values of LV mass by body size was more accurate at birth and progressively less precise with increasing age. Stroke work (stroke volume times systolic pressure) was closely related to LV mass (r2=.74). The explained variance of LV mass increased from 69% in the univariate regression with height2.7 to 82% in a multivariate model including height2.7, stroke work, and gender. In children and adolescents (younger than 18 years), height2.7 was the main determinant of LV mass, whereas during adulthood stroke work and gender were more important predictors of LV mass than height2.7. Thus (1) the influence of body growth on development of LV mass decreases after early infancy because of both the variability of hemodynamic load and the increasing effect of gender; (2) after adolescence, during adulthood, in normotensive, normal-weight individuals, the impact of hemodynamic load and male gender on LV mass is greater than the one of body size; and (3) an appreciable proportion of variability of LV mass remains unexplained with the studied models. This might be due to genotypic variations and/or measurement error.

Influence of obesity on left ventricular midwall mechanics in arterial hypertension.

The evaluation of the effect of obesity on left ventricular systolic performance may differ in relation to the method used to measure left ventricular function and to the type of study population. Whether obesity worsens left ventricular midwall mechanics in arterial hypertension has never been investigated. Accordingly, we assessed echocardiographic left ventricular midwall shortening-circumferential end-systolic stress relations in 156 normotensive and normal-weight (reference) adults, 94 normotensive and overweight (1985 National Institutes of Health partition values) to obese (body mass index > 30 kg/m2) adults, 263 hypertensive and normal-weight adults, and 224 hypertensive and overweight-to-obese adults. There was an inverse relation of midwall shortening to circumferential end-systolic stress in all groups (all P < .005). Left ventricular performance as a ratio of observed to predicted midwall shortening fell below the fifth percentile in 4 of 94 (4%) of overweight-to-obese normotensive individuals. Eighty-eight of 487 hypertensive subjects (18.1%) exhibited depressed midwall shortening as a percentage of the value predicted from wall stress, with no difference between normal-weight (50 of 263 [19%]) and overweight (38 of 224 [17%]) subjects. Sixty-one normotensive and 131 hypertensive subjects were frankly obese. After adjustment for sex and age, midwall shortening, as either absolute values or a percentage of predicted, was not statistically different among obese, overweight, and normal-weight subjects in both normotensive and hypertensive groups. For each quartile of observed-to-predicted midwall shortening ratio, obese subjects had greater left ventricular end-diastolic volume than normal-weight subjects among both normotensive and, more evidently, hypertensive subjects. A predicted midwall shortening was generated from both wall stress and left ventricular volume with the use of multiple regression analysis. High body mass index, mean blood pressure, aging, and male sex independently predicted low afterload and left ventricular volume-independent midwall left ventricular performance (multiple R = .31, P < .0001). Thus, (1) midwall left ventricular systolic performance in asymptomatic overweight or frankly obese individuals is comparable to that in normal-weight individuals in both the presence and absence of arterial hypertension; (2) however, maintenance of normal life ventricular performance in obese individuals is associated with the use of Starling reserve; and (3) this compensatory mechanism is especially evident when arterial hypertension and obesity coexist.