Left ventricular mass correlates with fat-free mass but not fat mass in adults.

BACKGROUND: Left ventricular mass is associated with body size, obesity and blood pressure. Echocardiography is routinely used to estimate this parameter, which is usually indexed to body surface area to allow comparisons to be made between individuals and groups of different body size. However, in obese subjects, using left ventricular mass indexed to body surface area may inappropriately normalize left ventricular mass. OBJECTIVES: The aim of this study was to investigate the relationships between left ventricular mass and body composition and to determine the best determinants of left ventricular mass. SUBJECTS AND METHODS: Echocardiography and dual-energy X-ray absorptiometry were performed in 106 subjects under primary care. Half were hypertensive subjects and the others were normotensive age- and sex-matched control subjects. Univariate correlations were studied between left ventricular mass and height, height1.5, height2.7, weight, body surface area, body mass index, waist: hip ratio, fat-free mass, bone mineral content and fat mass. Stepwise multiple linear regression was performed to determine the best determinants of left ventricular mass. RESULTS: Fat-free mass was correlated with left ventricular mass (r = 0.53, P = 0.0001) and was the only independent predictor of left ventricular mass (R2 = 0.30, P= 0.0001) by multivariate analysis. Fat mass did not correlate with left ventricular mass (r= -0.005, P= 0.96). Other measures of body size, including body surface area, waist: hip ratio, bone mineral content, weight, height, height 1.5, height2.7 and body mass index all were correlated with, but were not independent determinants of, left ventricular mass. CONCLUSIONS: Left ventricular mass is independently determined by fat-free mass but by no other measures of body size or composition. Specifically, left ventricular mass was neither correlated with nor determined by fat mass. None of the other measures of body size determined left ventricular mass. It may be more appropriate to index left ventricular mass to fat-free mass rather than to measures of body size which include fat mass.     

Evaluation of the best indicator of muscle mass in community-dwelling elderly persons

AIM: The purpose of this study was to determine the best way to indicate muscle mass of community-dwelling elderly men and women. METHODS: We recruited 398 elderly men and women (age range, 61-96, years) who use a community center and live in a metropolitan suburb. We measured appendicular and whole body muscle mass by using bioelectrical impedance analysis and analyzed our results in relation to indicators of physical function. We assessed muscle mass with no adjustment, adjustment by body mass, and adjustment by body height. RESULTS: In men, appendicular muscle mass adjusted by body mass correlated significantly with 10-m obstacle walking time, and whole body muscle mass adjusted by body mass correlated significantly with all indicators physical function except five chair stands and maximum walking speed. In women, appendicular and whole body muscle mass adjusted by body mass correlated significantly with all indicators of physical function. However, appendicular and whole body muscle mass adjusted by body height were unrelated to indicators of physical function. CONCLUSIONS: Only whole body muscle mass adjusted by body mass was related to physical function in both men and women. This finding suggests that whole body muscle mass adjusted by body mass is the best indicator of muscle mass in community-dwelling elderly persons.     

体重及其构成成分对2型糖尿病患者骨量的影响

目的探讨体重及其构成成分对2型糖尿病（T2DM）患者骨量的影响。方法DEXA测定131例T2DM患者及89名对照者的瘦体重、总体脂量、全身脂肪含量、全身骨密度（BMD）及骨矿含量（BMC）,计算BMI、校正骨矿含量（CBMC）,对比两组上述指标,分析体重及其构成成分与骨量关系。结果T2DM组体重、瘦体重及BMC大于对照组,两组间BMD、CBMC无差异。在T2DM组成员中,体重、瘦体重、总体脂量与骨量呈正相关,全身脂肪含量与骨量呈负相关。结论T2DM患者骨密度与正常人比较无下降,较高的体重、瘦体重及总体脂量是其骨量保护因素,瘦体重的保护作用更显著。     

The relationship between body composition and bone mineral density in postmenopausal Turkish women

In a retrospective cross-sectional study among 202 postmenopausal women aged 46–75 years, we aimed to investigate the relationship between body composition and bone mineral density (BMD) to determine whether fat mass or lean mass is a better determinant of BMD in Turkish postmenopausal women. Lumbar spine (L1–L4) and proximal femur BMD were measured by dual energy X-ray absorbsiometry. Body composition analysis was performed by bioelectric impedance method and fat mass, lean mass, and percent fat were measured. Both fat mass and lean mass were positively correlated with BMD at the lumbar spine and proximal femur, weight and body mass index. Lean mass was also positively correlated with height and negatively correlated with age and years since menopause (P < 0.01). The correlations of fat mass and lean mass with BMD at the lumbar spine and proximal femur remained significant after adjustment for age, years since menopause and height. When the lean mass was adjusted together with age, years since menopause and height, the significant relationship between the fat mass and BMD continued, however the significant correlation between the lean mass and BMD disappeared at all sites after adjustment for fat mass. In multiple regression analyses, fat mass was the significant determinant of all BMD sites. Our data suggest that fat mass is the significant determinant of BMD at the lumbar spine and proximal femur, and lean mass does not have an impact on BMD when fat mass was taken into account in Turkish postmenopausal women.     

Adipose tissue stimulates bone growth in prepubertal children

CONTEXT: Fat mass represents a positive influence on bone mass in adults, independently of other factors such as lean mass, but whether a similar action occurs in children is unclear. OBJECTIVE: Our objective was to examine the relationship between fat mass and bone mass in children. DESIGN AND SETTING: We conducted combined cross-sectional and prospective analyses at university research clinics. PARTICIPANTS: Participants included children aged 9.9 yr from a large population-based birth cohort in southwest England. OUTCOMES: Relationships between total body fat mass were measured by dual-energy x-ray absorptiometry at age 9.9 yr, and 1) total-body-less-head bone mass and area at age 9.9 and 2) increase in bone mass and area over the following 2 yr. RESULTS: There was a strong positive relationship between total body fat mass and total-body-less-head bone mass and area, even after adjustment for height and/or lean mass (P < 0.001). There was a similar positive association between total body fat mass and increase in bone mass and area over the following 2 yr in boys and Tanner stage 1 girls. In contrast, no association was present between fat mass and gain in bone mass and size in Tanner stage 2 girls, whereas a negative association was seen in Tanner stage 3 girls (puberty-fat mass interaction, P < 0.001). CONCLUSIONS: In prepubertal children, fat mass is a positive independent determinant of bone mass and size and of increases in these parameters over the following 2 yr, suggesting that adipose tissue acts to stimulate bone growth. However, this relationship is attenuated by puberty.     

Relationship of obesity with osteoporosis

CONTEXT: The relationship between obesity and osteoporosis has been widely studied, and epidemiological evidence shows that obesity is correlated with increased bone mass. Previous analyses, however, did not control for the mechanical loading effects of total body weight on bone mass and may have generated a confounded or even biased relationship between obesity and osteoporosis. OBJECTIVE: The objective of this study was to reevaluate the relationship between obesity and osteoporosis by accounting for the mechanical loading effects of total body weight on bone mass. METHODS: We measured whole body fat mass, lean mass, percentage fat mass, body mass index, and bone mass in two large samples of different ethnicity: 1988 unrelated Chinese subjects and 4489 Caucasian subjects from 512 pedigrees. We first evaluated the Pearson correlations among different phenotypes. We then dissected the phenotypic correlations into genetic and environmental components with bone mass unadjusted or adjusted for body weight. This allowed us to compare the results with and without controlling for mechanical loading effects of body weight on bone mass. RESULTS: In both Chinese and Caucasian subjects, when the mechanical loading effect of body weight on bone mass was adjusted for, the phenotypic correlation (including its genetic and environmental components) between fat mass (or percentage fat mass) and bone mass was negative. Further multivariate analyses in subjects stratified by body weight confirmed the inverse relationship between bone mass and fat mass, after mechanical loading effects due to total body weight were controlled. CONCLUSIONS: Increasing fat mass may not have a beneficial effect on bone mass.     

Both lean and fat body mass associate with blood pressure

High body mass index (BMI) is known to be associated with elevated blood pressure (BP). The present study aims to determine the relative importance of the two components of BMI, fat mass and lean body mass index, on BP levels.We assessed body composition with bioimpedance and performed 24 hour ambulatory BP measurements in 534 individuals (mean age 61 ± 3 years) who had no cardiovascular medication. Fat mass index and lean mass index were calculated analogously to BMI as fat mass or lean body mass (kg) divided by the square of height (m²).Both fat mass index and lean mass index showed a positive, small to moderate relationship with all 24 hour BP components independently of age, sex, smoking, and leisure-time physical activity. There were no interaction effects between fat mass index and lean mass index on the mean BP levels.Adult lean body mass is a significant determinant of BP levels with an equal, albeit small to moderate magnitude as fat mass. Relatively high amount of muscle mass may not be beneficial to cardiovascular health.     

Left ventricular mass and correlated atherosclerotic risk factors in young adolescents: report from Chin-Shan community cardiovascular study in Taiwan

Various subclinical disease indicators can be used as an early stage marker of atherosclerosis. Left ventricular (LV) mass has been related to cardiovascular morbidity and mortality. The distribution of LV mass in Chinese is rarely studied and nothing is known about its relationships with various atherosclerotic risk factors in young teenagers, in particular, aspects of lipid profiles. We performed a community-based survey of 523 males and 555 females, aged 12-15, in Chin-Shan, a suburb area near Taipei, Taiwan. LV mass was calculated from the Penn convention. Normalized LV mass by height with power of 2.7 was defined. LV mass and normalized LV mass were significantly greater in males than in females. There were significant positive correlation coefficients between LV mass and age, blood pressure, body mass index, low density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) B, fasting insulin levels and significant negative correlation coefficients between LV mass and high density lipoprotein cholesterol (HDL-C) and Apo A1 level in both genders. Multiple linear regression models showed gender and body mass index (BMI) were important factors associated with LV mass or normalized values for adolescents. Age and systolic blood pressure were also significant predictors of LV mass, but not of normalized LV mass values. LV mass values were found to be negatively associated with HDL-C values at marginal statistically significant level. Age and BMI are the most significant factors of echocardiographic LV mass distributions in young adolescent in Taiwan. LV mass may also be associated with atherosclerotic risk factors.     

Noninvasive quantification of jeopardized myocardial mass in dogs using 2-dimensional echocardiography and thallium-201 tomography

The evaluation of jeopardized myocardial mass is important in defining the effect of interventions during myocardial infarction. To quantitate the in vivo mass at risk, 2-dimensional echocardiography (2-D echo) and thallium-201 single-photon emission computed tomography (SPECT) was performed in 10 closed-chest dogs after circumflex coronary artery occlusion. The 2-D images were manually digitized to compute left ventricular (LV) mass using a modified Simpson's rule algorithm. This measure of LV mass correlated well with the actual LV mass (r = 0.97). Perfused myocardial mass was estimated from thallium SPECT images 4 hours after occlusion using a region-growing algorithm. After the dogs were killed, the jeopardized mass was outlined using a dual perfusion staining technique using triphenyltetrazolium chloride and Evans blue dye. The actual perfused mass was well estimated by the thallium images (r = 0.96). The noninvasively determined mass at risk was calculated as: 2-D mass — thallium SPECT mass, and correlated well with the pathologically determined mass at risk (r = 0.91). Thus, the jeopardized mass may be determined noninvasively by using 2-D echo and thallium-201 tomography. This approach may provide further information regarding the effect of intervention therapy on jeopardized myocardium.     

以生物电阻法检测的身体组成成分与女性骨量的关系

目的 探讨体内的体脂和非体脂对绝经前和绝经后妇女骨密度(BMD)的作用。方法 282例绝经前和205例绝经后妇女参加本研究,用双能X线骨密度仪测定腰椎和股骨颈BMD,用生物电阻法测定体脂和非体脂,同时测量身高、体重、腰围、臀围,并计算体重指数(BMI)和腰臀围比(WHR)。结果 体脂和非体脂与绝经前、绝经后妇女腰椎和股骨颈BMD均呈显著正相关(P＜0．01),多元逐步回归分析显示,在绝经前妇女中,非体脂和年龄是腰椎BMD的独立影响因素(R^2=0．077,P=0．000),非体脂、年龄和BMI是影响股骨颈BMD的决定因素(R^2=0．130,P=0．000),在绝经后妇女中,体脂和年龄是影响腰椎和股骨颈BMD的决定因素(R^2分别为0．153和0．184,P=0．000)。结论 体脂和非体脂对绝经前和绝经后妇女BMD的作用不同,非体脂是决定绝经前妇女骨量的重要因素,而体脂是影响绝经后妇女骨量的重要因素。     

Low lipoprotein lipase mass in preheparin serum of type 2 diabetes mellitus patients and its recovery with insulin therapy

There exists lipoprotein lipase mass in preheparin serum, even though the activity is scarcely found. We studied the preheparin serum lipoprotein lipase mass levels (prehaparin LPL mass) in type 2 diabetes mellitus patients and the effect of insulin therapy on the levels of preheparin LPL mass. In 40 type 2 diabetes mellitus patients, preheparin LPL mass were measured by the sandwich enzyme-linked immunosorbent assay (ELISA), and were compared with those of non-diabetic healthy control. The correlation between preheparin LPL mass and Hemoglobin A(1c) (HbA(1c)), serum lipids were studied. Preheparin LPL mass were measured before and after insulin therapy. Preheparin LPL mass of type 2 diabetes mellitus patients was significantly lower than that of non-diabetic healthy control. In diabetic patients, preheparin LPL mass were negatively correlated with HbA(1c). Fifteen patients started to take insulin therapy. Preheparin LPL mass increased significantly at 4th week, when fasting blood glucose decreased. These results suggested that preheparin LPL mass was greatly regulated by insulin action.     

Commingling analysis of generalized body mass and composition measures: the Québec Family Study.

Human body mass and composition are heterogeneous phenotypes resulting from the combined effects of genes, environmental factors, and their interactions. In order to gain an understanding of the individual genetic determinants leading to obesity, we have initiated a systematic analysis of several measures of fatness and its phenotypes including: the body mass index (wt/ht2), fat mass, fat-free (lean) mass, the ratio of fat mass over fat-free mass, percent body fat, and a fat mass index (fat mass/ht). In this report, we examine the distributions of these age and sex adjusted variables in a large family study from Québec in terms of evidence for commingling and skewness, and evaluate the inter-relationships among the measures. Fat mass, fat-free mass and the fat mass index conceptually represent primary variables in that they are quantitative measures of relevant components of total body weight; the hypothesis of a single distribution was inferred for each of these primary measures, with significant residual skewness except for fat mass. In general, offspring (8-26 years old) distributions were more positively skewed than parent (30-60 years old) distributions. The remaining variables (body mass index, fat mass to fat-free mass ratio, and percent body fat) are indexes combining information on fat and fat-free mass into single measures. Although offspring data were consistent with a single skewed distribution, commingling was found in the parents in each case. The prominent heterogeneity between generations suggests that there may be significant developmental (genetic or environmental) effects in the transition during growing years to adult pattern phenotypes, particularly for the complex indicators of body composition.     

Value of a simple echocardiographic linear predictor of left ventricular mass in systemic hypertension

The need for calculations limits the clinical use of left ventricular (LV) mass. Because LV mass is strictly dependent on wall thickness for every given value of LV external dimension, we tested the clinical value of the sum of LV external dimension plus ventricular septal thickness plus posterior wall thickness as predictors of standard LV mass. We studied 295 healthy normotensive subjects and 1,686 subjects with systemic hypertension, followed up for 1 to 9 years. In the normotensive group, the predictor of LV mass showed a very close association with standard LV mass according to an allometric model (LV mass [g] = 0.230 x LV mass predictor [cm]3.01), with 99.7% of LV mass variability explained by the model. Also, in the hypertensive group, the LV mass predictor showed a very close allometric relation to standard LV mass (R2 = 0.998). During follow-up there were 154 cardiovascular morbid events and 50 deaths from all causes. The risk of cardiovascular morbid events and that of death increased to a similar extent with LV mass normalized by body surface area, height or height2.7, as well as with the LV mass predictor. The risk estimates for cardiovascular morbidity and all-cause mortality provided by models including either LV mass predictor or LV mass uncorrected or corrected by height, body surface area, or height2.7 did not show any statistical differences between the different models. In conclusion, the sum of LV external dimension plus ventricular septum thickness plus posterior wall thickness, easily measurable from the M-mode echocardiographic tracing, very closely predicts standard LV mass in adult hypertensive subjects. The prognostic value of this measure does not differ from that of standard LV mass.     

Measurement of adherent cell mass and growth

The characterization of physical properties of cells such as their mass and stiffness has been of great interest and can have profound implications in cell biology, tissue engineering, cancer, and disease research. For example, the direct dependence of cell growth rate on cell mass for individual adherent human cells can elucidate the mechanisms underlying cell cycle progression. Here we develop an array of micro-electro-mechanical systems (MEMS) resonant mass sensors that can be used to directly measure the biophysical properties, mass, and growth rate of single adherent cells. Unlike conventional cantilever mass sensors, our sensors retain a uniform mass sensitivity over the cell attachment surface. By measuring the frequency shift of the mass sensors with growing (soft) cells and fixed (stiff) cells, and through analytical modeling, we derive the Young's modulus of the unfixed cell and unravel the dependence of the cell mass measurement on cell stiffness. Finally, we grew individual cells on the mass sensors and measured their mass for 50+ hours. Our results demonstrate that adherent human colon epithelial cells have increased growth rates with a larger cell mass, and the average growth rate increases linearly with the cell mass, at 3.25%/hr. Our sensitive mass sensors with a position-independent mass sensitivity can be coupled with microscopy for simultaneous monitoring of cell growth and status, and provide an ideal method to study cell growth, cell cycle progression, differentiation, and apoptosis.     

Determination of left ventricular mass using single-photon emission computed tomography

To test the hypothesis that single-photon emission computed tomography (SPECT) could actually determine left ventricular LV mass in humans, SPECT measurements of LV mass were compared with LV mass determined by cineangiography in 12 patients with normal coronary arteries and LV function. Repeat SPECT determinations of LV mass were carried out in 5 patients. Projection images of the left ventricle were acquired after intravenous injection of thallium-201 (TI-201) using a rotating gamma camera. Transverse sections were reconstructed by filtered backprojection. The boundary of LV uptake of TI-201 in each transverse section was defined using a 3-dimensional threshold detector. Scintigraphic LV mass (total number of voxels demonstrating LV TI-201 uptake X voxel volume X specific gravity of myocardium) was compared with angiographic LV mass. There was good correlation between LV mass determined by SPECT and that determined by cineangiography. Mean angiographic LV mass was 208 +/- 45 g (+/- standard deviation). Mean SPECT LV mass was 204 +/- 42 g. Linear regression analysis revealed the following relation: SPECT LV mass = 0.76 X angiographic LV mass + 46.1 (r = 0.82, root-mean-square deviation from regression = 24.7). The SPECT values of LV mass varied an average of 10.4 +/- 4.6% (+/- standard deviation) in the 5 patients in whom 2 determinations were made. Thus, SPECT of TI-201 can accurately measure LV mass in humans.     

Body mass index and blood pressure influences on left ventricular mass and geometry in African Americans: The Atherosclerotic Risk In Communities (ARIC) Study

A unique interaction between the influences of body mass index and blood pressure on left ventricular mass index and geometry may contribute to the higher prevalence of left ventricular hypertrophy in African Americans. This cross-sectional study assessed separate and joint influences of body mass index and blood pressure on left ventricular mass index and geometry in 1729 African American participants of the Atherosclerotic Risk in Communities Study. The association between both left ventricular mass index and relative wall thickness and body mass index in each blood pressure category and between these variables and blood pressure in each body mass index category was assessed adjusting for age, diabetes status, hypertension medication, and smoking status. We found that left ventricular hypertrophy and concentric geometry were highly prevalent and that body mass index and blood pressure were independently associated with left ventricular mass index. The adjusted association between blood pressure and left ventricular mass index was stronger with higher body mass index categories; however, there was no significant interaction suggesting merely an additive relationship (not synergistic/multiplicative as tested for in the interaction analysis). Although relative wall thickness was greater with higher categories of body mass index and blood pressure, the mean difference in relative wall thickness between body mass index and blood pressure categories was not statistically significant. The effect on left ventricular geometry as measured by relative wall thickness supports the theory that there is a pathophysiological component in the mechanism of hypertrophy.     

Preheparin serum lipoprotein lipase mass level: the effects of age, gender, and types of hyperlipidemias.

To clarify the factors regulating preheparin serum lipoprotein lipase mass (preheparin LPL mass), the correlations between preheparin LPL mass and age, gender and types of hyperlipidemias were investigated in 377 persons who underwent annual health examinations. Preheparin LPL mass level did not significantly differ in individuals from 19 to 70 years old, for both men and women. Preheparin LPL mass level correlated negatively with triglyceride (TG), positively with high density lipoprotein-cholesterol (HDL-C), and not at all with total cholesterol (TC) or low density lipoprotein-cholesterol (LDL-C). Preheparin LPL mass levels were apparently higher in women than in men, but when serum lipid levels were adjusted, preheparin LPL mass levels were identical. In type IV and IIb hyperlipidemia, preheparin LPL mass levels were lower than in type IIa patients and in normals. Remnant positive individuals had lower levels of preheparin LPL mass than the negative individuals. In conclusion, preheparin LPL mass levels were not affected by aging and gender, but were lower in the conditions in which TG catabolism was disturbed, indicating that preheparin LPL mass might reflect somewhat the amount of LPL working in the body.     

Determinants of left ventricular mass in a French male population.

The aim of this analysis was to study the determinants of left ventricular mass evaluated by echocardiography. A total of 843 healthy men aged 47-61 years, who had a standard health check-up at the Centre d'Investigations Preventives et Cliniques (IPC Center), were included in the study. None of the subjects were being treated for cardiovascular disease at the time of their visit and each had a standard clinical and biological examination. The answers to a lifestyle questionnaire, weight at 20 years and family history were recorded. All subjects had an echocardiogram to evaluate left ventricular mass. Left ventricular mass values were adjusted for height using the ratio of left ventricular mass to height. Current body mass index, systolic and diastolic blood pressure, brachial circumference, triglycerides and a family history of sudden death were positively associated with this ratio (p < 0.01). Physical activity and tobacco consumption were associated with left ventricular mass. Body mass index at 20 years, variation of body mass index since that age, systolic blood pressure and family history of sudden death explain 21% of the ratio of left ventricular mass/height (body mass index at 20 years: 11.8%; variation of body mass index: 5.1%; systolic blood pressure: 2.3%; and family history of sudden death: 0.4%). The other factors explain only 1.4% of this variance and were not significantly associated with the ratio of left ventricular mass to height. Body mass index at 20 years was the strongest determinant of left ventricular mass, suggesting that left ventricular mass at middle age is in large measure determined much earlier in life. A family history of sudden death before the age of 60 years is also an important determinant of left ventricular mass, independent of obesity. These factors must be taken into account in order to prevent an increase in left ventricular mass.     

Body composition and bone mass in post-menopausal women

OBJECTIVE: We aimed to assess total body composition and to study the interrelationships between fat and lean tissue mass with total and regional bone mass in healthy British post-menopausal women. DESIGN AND PATIENTS: Total body composition and regional bone mass were measured in 97 healthy post-menopausal women recruited from the general community. The mean age was 57.9 years, range 49-65. MEASUREMENTS: Total body composition (fat, lean tissue and bone mineral) and regional bone density in the lumbar spine and femur were measured by dual energy X-ray absorptiometry on a Lunar DPX. RESULTS: Significant negative correlations with age were found for total body bone mineral density (r = -0.200, P = 0.049), and lumbar spine bone mineral density (r = -0.28, P = 0.006); the calculated rate of bone loss from these two sites was 0.33 and 0.7% per annum respectively. Fat tissue mass showed a positive correlation with age (r = 0.22, P = 0.03). High correlations were observed between total body and regional bone mineral density (r = 0.755-0.829, P < 0.001). After adjustment for age and lean mass, statistically significant correlations were seen between fat tissue mass and all bone mass measurements (P < 0.01-0.001), the strongest correlations being found for total body bone mineral content and density (r = 0.477 and 0.488 respectively). Lean tissue mass showed a strong correlation with total body bone mineral content (r = 0.580, P < 0.001), after adjustment for age and fat mass; it was less strongly correlated with other bone mass measurements than fat mass, showing only weak correlations with total body, trochanteric and lumbar spine bone mineral density (r = 0.228-0.246, P < 0.05). Age-adjusted body weight showed stronger correlations with total and regional bone mass than did either body mass index or height. CONCLUSIONS: Both fat and lean tissue mass are related to total and regional bone mass in post-menopausal women, the relationship being strongest for fat mass. Body weight shows stronger correlations with bone mass than either height or body mass index. In view of the direction and magnitude of changes in fat, lean tissue and bone mineral after the menopause, adiposity and muscularity are more likely to be determinants of peak bone mass than of the rate of post-menopausal bone loss.     

Relation of increase in adiposity to increase in left ventricular mass from childhood to young adulthood

This study evaluated the influence of adiposity on the progression of left ventricular (LV) mass from childhood to adulthood and the relation of LV mass to insulin resistance in young adulthood. One hundred thirty-two healthy children recruited into a longitudinal study at a mean age of 13 years and reevaluated at 27 years, at which time insulin resistance studies were also performed, were studied. Echocardiographic assessment of LV mass was made and indexed for height. Body mass index (BMI) at 13 years was highly correlated with BMI at 27 years, as was LV mass index at 13 and 27 years. The cross-sectional correlation of LV mass index and BMI at 13 years (r = 0.38, p < 0.0001) had strengthened considerably by 27 years (r = 0.55, p < 0.0001). A BMI increase > or = 5.5 kg/m2 from 13 to 27 years was associated with a significantly greater increase in the LV mass index (p < 0.0001) than a BMI change < 5.5 kg/m2, and this relation was similar in children who were thin and heavy at baseline. In young adulthood, the relation of LV mass index to lean mass was weaker than that of LV mass index to fat mass. The association of LV mass with insulin resistance was dependent on adiposity. In conclusion, adiposity and LV mass are related in childhood, and this association tracks and becomes stronger in young adulthood. Moreover, the increase in LV mass from childhood to young adulthood is related to the degree of increase in BMI, independent of BMI at 13 years, suggesting that an excessive increase in LV mass could be limited by controlling gain in body fat during adolescence.