The human obesity gene map: the 1996 update

An update of the human obesity gene map up to October 1996 is presented. Evidence from Mendelian disorders exhibiting obesity as a clinical feature, single-gene mutation rodent models, quantitative trait loci uncovered in crossbreeding experiments with mouse, rat, and pig models, association and case-control studies with candidate genes, and linkage studies with genes and other markers is reviewed. All chromosomal locations of the animal loci are converted into human genome locations based on syntenic relationships between the genomes. A complete listing of all these loci reveals that only 4 of the 24 human chromosomes are not yet represented, i.e., 9, 18, 21, and Y. Several chromosome arms are characterized by the presence of several putative loci. The following arms include at least three such loci: 1p, 1q, 3p, 4q, 6p, 7q, 8p, 8q, 11p, 11q, 15q, 20q, and Xq. Studies with negative association and linkage results are also reviewed.

Monitoring high-intensity endurance exercise with heart rate and thresholds

Ventilatory and lactate thresholds have been proposed as tools to establish the highest steady-state intensity sustainable during prolonged physical exercise. The purposes of this study were to clarify whether the intensity at the ventilatory threshold could be sustained during prolonged high-intensity exercise and if the corresponding work rate, pulmonary ventilation, and blood lactate concentration could also be maintained. Fifteen young and healthy male subjects were submitted to a VO2max test on ergocycle and a 90-min high-intensity ergocycle endurance exercise test. During the 90-min exercise test, subjects were able to maintain an intensity corresponding to a heart rate 5 beats.min-1 lower than that predetermined from the ventilatory threshold. Heart rate, FeO2, and FeCO2 were stable during the period from 20 to 80 min, VO2 was constant from 30 to 80 min, while work output, pulmonary ventilation, blood lactate, and VCO2 decreased significantly over the 90-min performance. These results show that physiological parameters near the ventilatory threshold are not interchangeable and that some cannot be used to monitor high-intensity long term exercise. Moreover, they clearly demonstrate that the blood lactate concentration fluctuates substantially during a 90-min endurance performance and cannot predict the highest work intensity that can be sustained during prolonged exercise without fatigue. However, heart rate and VO2 at the ventilatory threshold seem to be more suitable markers for that purpose.

Adenovirus-mediated gene transfer to the brain: methodological assessment

The purpose of this short review is to analyse major advantages and limitations of the adenovirus (Ad), specifically with relevance to its use as a vector for gene transfer to the brain. The characteristics of Ad transduction include: the relative absence of cell type specificity; the limited spatial spread of the virus; and the long-term expression of the transgene. In the central nervous system, in contrast to that which occurs in other organs, Ad transduction in the adult does not systematically provoke cell death. Nevertheless, a proportion of the transduced cells do die, and this represents a conspicuous problem. Mechanisms leading to cell death in the brain may include immune rejection and inflammation-related toxicity, although this would not explain all of the results, and direct toxicity related to either inappropriate preparation or the transduction itself. Taking into account uncertainties concerning the innocuousness of Ad transduction, it may seem unwise to envisage Ad gene therapy for diseases that are not life-threatening and/or benefit from adequate drug or surgical treatments (e.g. Parkinson's disease or epilepsy). Ad vectors may not be easily used either in diseases displaying major immune dysfunction (e.g. multiple sclerosis). In contrast, malignant brain tumors and numerous neurodegenerative diseases (such as Huntington's, Alzheimer's diseases or amyotrophic lateral sclerosis) are directly life-threatening and deprived of any adequate treatment. They may be appropriate targets for Ad-mediated gene therapy, once both the vector and the gene of interest have been defined and optimized.

The surgical treatment of vulvar vestibulitis syndrome: a follow-up study

This study evaluated the effectiveness of vestibulectomy in relieving coital pain and improving sexual function in women diagnosed with vulvar vestibulitis. Vulvar vestibulitis syndrome, a chronic, nonspecific inflammation of the vulvar vestibule, probably represents the most frequent subtype of premenopausal dyspareunia. Participants were 38 women who underwent vestibulectomy at a university hospital between 1986 and 1994. Telephone interviews were conducted to assess whether vestibulectomy or other subsequent treatments affected coital pain and sexual functioning. Length of postoperative follow-up ranged from 1.1 to 10 years, with a mean of 3.3 years. Vestibulectomy yielded a positive outcome for 63.2% of the participants and moderate to no improvement for the other 36.8%. The surgery was linked to a significant increase in intercourse frequency for the entire sample and to an increase in oral and manual stimulation for the women with successful surgical outcomes. No other factors were significantly associated with treatment outcome.

[Sensitivity and specificity of thyreostimuline (TSH) determination on filter paper for the diagnosis of hypothyroidism in the elderly]

The aim of this study was to measure the prevalence of hypothyroidism in 239 elderly patients and to determine the validity of TSH assay on blood dried on filter paper (spot-test) for the diagnosis of hypothyroidism. The sensitivity and specificity of the spot-test were evaluated in a subgroup of 177 subjects. The prevalence of hypothyroidism was 14.2% (34/239). The spot-test did not give satisfactory results for the diagnosis of hypothyroidism in elderly subjects. Due to the lack of specificity, most of the positive results were false positives and the clinician had to rely on laboratory determination of plasma TSH level to confirm hypothyroidism in half of the patients. We do not recommend the spot-test for the diagnosis of hypothyroidism in the elderly. Laboratory assay of plasma TSH is required for confirming hypothyroidism in the elderly.

Associations between 12 year changes in body fatness and lipoprotein-lipid levels in men and women of the Québec Family Study

OBJECTIVE

To investigate the associations between 12 year changes in body composition, subcutaneous fat distribution vs changes in plasma lipoprotein-lipid levels.

DESIGN

12 year prospective study.

SUBJECTS

A sample of 95 women and 93 men of the Québec Family Study initially tested in 1980.

MEASUREMENTS

Various body fatness variables as well as fasting plasma lipoprotein-lipid concentrations performed both in 1980 and 1992.

RESULTS

In both 1980 and 1992, a high body fat mass and an elevated accumulation of subcutaneous trunk fat were associated with a significant deterioration in the plasma lipoprotein-lipid profile. Furthermore, correlation analysis performed on differences noted during the 12 years follow-up revealed significant associations between changes in body fat mass and in plasma cholesterol [r = 0.52, P < 0.0005] in women. In both men and women, an increased body fat mass was associated with an increased CHOL/HDL-cholesterol ratio [r = 0.37, P < 0.01 (men) and r = 0.54, P < 0.0005 (women)]. Correlations between changes in fat mass and plasma lipids were generally of higher magnitude in women than in men. Changes in subcutaneous trunk fat were associated with changes in plasma HDL-chol levels (r = -0.22, P < 0.05) in men whereas in women, changes in trunk adiposity were related to changes in both plasma CHOL (r = 0.25, P < 0.05) and TG (r = 0.32, P < 0.005) levels.

CONCLUSION

These results support the notion that the increased adiposity observed among aging adult men and women is a significant component of the deterioration in the plasma lipoprotein-lipid profile noted over a 12 year follow-up period.

[Electric burns: epidemiological and therapeutic aspects]

OBJECTIVES

A retrospective study of patients with electrical burns was conducted to choose criteria for initial dispatching and establish a treatment protocol for out patient management.

METHODS

The study included 67 patients injured by electrical current and admitted at Edouard Herriot Hospital Burns Unit between January 1st 1990 and January 1st 1993.

RESULTS

Low-voltage currents (< 1000 Volts) responsible for serious and immediate cardio-vascular diseases occurred in domestic accidents, mostly with children. High-voltage current (> 1000 Volts) responsible for deep burn injuries occurred in accidents at work and mostly with adults. Twenty-two were outpatients and 45 were admitted at once. Two died on admission, 24 were hospitalized less than five days, 11 required repeated surgical treatments and a long stay at hospital, and 8 were severely burned and were admitted to the intensive-care unit. Two required continuous venovenous hemodialysis for three weeks. Morbidity of the last three groups was nil, morbidity remained high in term of functional and aesthetic after-effects.

CONCLUSION

Information on prevention of electrical burns should be intensified.

The HERITAGE Family Study: quality assurance and quality control

The HERITAGE (HEalth, RIsk factors, exercise Training And GEnetics) Family Study is the first multicenter family clinical trial of its kind. Conducted by a consortium of five universities in the United States and Canada, the study has as its primary goal to document the role of the genotype in the cardiovascular, metabolic, and hormonal responses to aerobic exercise training. A comprehensive protocol was implemented at four Clinical Centers (CC) for the generation of data on sedentary subjects. This group included 450 caucasians from 90 nuclear families (father, mother, three children) and 200 black subjects from 40 to 100 family units over a 5-year period. The entire family was tested before and after a 20-week exercise training program. The fifth participating center, the Data Coordinating Center (DCC), is responsible for data management and data analysis. A Consortium Coordinating Center (CCC) responsible for the overall coordination and direction of the study was established at the Quebec CC. Quality assurance and quality control are jointly coordinated by the CCC and the DCC. A multicenter study of this magnitude requires careful standardization of all procedures and constant monitoring of quality control at all levels of operation. This report describes the quality assurance and quality control measures implemented in the HERITAGE Family Study, including some examples with real data.

Familial correlations in the Québec family study: cross-trait familial resemblance for body fat with plasma glucose and insulin

This study represents one component in our investigation of the familial factors underlying the insulin resistance (or metabolic) syndrome involving obesity, hyperinsulinaemia, glucose intolerance, dyslipidaemia, and hypertension. Here we examine the cross-trait familial resemblance between four measures of body size (two assessing total fat [body mass index and sum of six skinfolds] and two assessing fat patterning [ratio of trunk skinfold sum to extremity skinfold sum, adjusted and unadjusted for total subcutaneous fat]) with fasting plasma levels of glucose, insulin, and the ratio of insulin to glucose (IGR) in non-diabetic families participating in phase 1 of the Québec Family Study. A bivariate familial correlation model assessed both intraindividual (e.g. father's body size with father's insulin) and interindividual (e.g. father's body size with son's insulin) cross-trait associations. Intraindividual correlations suggested a greater degree of cross-trait associations for body fat (rather than fat distribution) measures with insulin and the IGR (rather than with glucose) levels. While the intraindividual correlations were significant for most cross-trait comparisons, only the sum of six skinfolds evidenced any familial association (i.e. interindividual resemblance) with insulin and the IGR. Specifically, cross-trait parent-offspring (but not sibling or spouse) correlations were significant, with a bivariate familiality estimate (i.e. polygenic and/or common familial environment) of about 8%. While the lack of sibling correlations does not suggest a simple familial hypothesis, a more complex genetic effect underlying the common covariation between total body fat with insulin and IGR cannot be ruled out.

A single threshold value of waist girth identifies normal-weight and overweight subjects with excess visceral adipose tissue

Our objective was to determine threshold values of waist girth, waist-to-hip ratio (WHR), and sagittal diameter corresponding to an accumulation of visceral adipose tissue of 130 cm2 and to verify whether these threshold values could be influenced by sex, age, menopausal status, and the degree of obesity. From the regression equations computed in the total sample of 213 men [aged (mean+/- SD) 37.8 +/- 12.2 y] and 190 women (aged 37.3 +/- 12.1 y), a waist girth of approximately 95 cm in both sexes, WHR values of 0.94 in men and of 0.88 in women, and sagittal diameters of 22.8 cm in men and 25.2 cm in women corresponded to a visceral adipose tissue area of 130 cm2. In both sexes, threshold values of waist girth corresponding to critical amounts of visceral adipose tissue were generally lower in subjects who were > or = 40 y old (approximately 90 cm) than in younger individuals (approximately 100 cm). Similar differences were found for WHR and sagittal diameter threshold values. Finally, threshold values of waist girth corresponding to critical amounts of visceral adipose tissue were essentially similar in normal-weight and overweight men and women, whereas threshold values of WHR were in general higher in normal-weight than in overweight subjects. In conclusion, our results suggest that the relations of anthropometric variables to visceral adipose tissue accumulation are age-specific. However, waist girth is likely to be a more convenient anthropometric correlate of visceral adipose tissue than the WHR because threshold values of waist girth corresponding to critical amounts of visceral adipose tissue do not appear to be influenced by sex or by the degree of obesity.

The Trp64Arg mutation of the beta3 adrenergic receptor gene has no effect on obesity phenotypes in the Québec Family Study and Swedish Obese Subjects cohorts

The beta adrenergic system plays a key role in regulating energy balance through the stimulation of both thermogenesis and lipid mobilization in brown and white adipose tissues in human and various animal models. Recent studies have suggested that a missense Trp64Arg mutation in the beta3 adrenergic receptor (ADRB3) gene was involved in obesity and insulin resistance. We have investigated the effect of this mutation on obesity-related phenotypes in two cohorts: the Québec Family Study (QFS) and the Swedish Obese Subjects (SOS). In QFS, no association was found between this mutation and body mass index (BMI), body fat including abdominal visceral fat, resting metabolic rate, various diabetes and cardiovascular risk factors, and changes in body weight and body fat over a 12-yr period. With the exception of RMR (P = 0.04), no evidence of linkage was detected between the mutation and phenotypes of QFS based on sib-pair data. In SOS, the frequency of the Trp64Arg allele was not significantly different between nonobese and obese female subjects and no association was found between the mutation and body weight gain over time. These findings do not support the view that there is an association between the Trp64Arg mutation in the ADRB3 gene and obesity.

The apoB-100 gene EcoRI polymorphism influences the relationship between features of the insulin resistance syndrome and the hyper-apoB and dense LDL phenotype in men

The aim of this study was to investigate whether the EcoRI polymorphism of the apolipoprotein B (apoB) gene influences the relationships between features of the insulin resistance syndrome and the dense LDL phenotype and apoB concentrations. A sample of 65 men was divided into two groups on the basis of the EcoRI genotype. Forty-four subjects were (+/+) homozygotes for the presence of the EcoRI restriction site that is associated with a glutamic acid at codon 4154. Twenty-one men were (+/-) heterozygotes for the absence of the restriction site resulting from a glutamic acid to a lysine substitution at codon 4154. In the (+/-) group, fasting plasma FFA levels were positively correlated with plasma apoB, LDL-apoB, and the LDL particle score that was calculated from the migration distances of LDL subspecies and their relative band intensities, reflecting the proportion of small dense LDL particles. However, these associations were not found among (+/+) subjects. The two genotypic groups were further divided into two subgroups on the basis of fasting FFA concentrations, and the LDL particle score and the LDL-apoB levels were compared. High FFA levels were associated with a higher proportion of small dense LDL particles, as reflected by a higher mean LDL particle score, irrespective of the genotype. However, the apoB-EcoRI polymorphism appeared to influence the association between high FFA levels and LDL-apoB concentrations because (+/-) heterozygotes with high FFA levels had higher LDL-apoB concentrations than (+/-) heterozygotes with low FFA levels. In addition, the integrated area under the curve of plasma insulin concentrations, measured in response to a 75-g oral glucose challenge, and the amount of visceral adipose tissue, measured by computed tomography, were positively associated with the LDL particle score only in (+/-) heterozygotes. When subjects were divided on the basis of insulin area (low vs. high) or visceral adipose tissue (low vs. high), (+/-) heterozygotes with high insulin area or with high levels of visceral adipose tissue had a higher mean LDL particle score than (+/-) heterozygotes with low insulin area or low visceral adipose tissue. However, among (+/+) homozygotes, low or high levels of insulin or visceral adipose tissue could not discriminate between men with large or small LDL particles. Therefore, (+/-) heterozygotes may be more susceptible to develop the dense LDL phenotype in presence of hyperinsulinemia and visceral obesity. Results of the present study suggest that the apoB-EcoRI polymorphism may exacerbate the alterations in the LDL particle (size and concentration) found among visceral obese-hyperinsulinemic men.

Seven-year changes in body fat and visceral adipose tissue in women. Association with indexes of plasma glucose-insulin homeostasis

OBJECTIVE

To study the associations between changes in body fatness, visceral adipose tissue (AT), and indexes of plasma glucose-insulin homeostasis over a 7-year follow-up period.

RESEARCH DESIGN AND METHODS

A sample of 30 nondiabetic women aged 35.2 +/- 5.6 (SD) years at baseline was studied.

RESULTS

Changes in visceral AT and in subcutaneous AT (measured by computed tomography) as well as changes in body fat mass (obtained by hydrostatic weighting) were significantly related to changes in fasting plasma insulin levels and in plasma insulin area measured after a 75-g oral glucose load (0.47 < or = r < or = 0.62; P < 0.01). Changes in visceral AT but not in body fat mass or in subcutaneous AT area were significantly associated with changes in plasma glucose area (r = 0.37; P < 0.05). When two subgroups of women with similar mean increases in body fat mass but with either small or large increases in visceral AT were compared, the subgroup with the largest gain in visceral AT showed the greatest deterioration in indexes of plasma glucose-insulin homeostasis. On the other hand, when two subgroups with similar mean increases in visceral AT but with different changes in body fat mass were compared, both subgroups showed similar changes in plasma glucose and insulin concentrations.

CONCLUSIONS

Results of this 7-year follow-up study in women suggest that changes in indexes of plasma glucose-insulin homeostasis are significantly associated with changes in visceral AT, even after control for changes in body fat mass.

A major gene for resting metabolic rate unassociated with body composition: results from the Québec Family Study

A major gene hypothesis for resting metabolic rate (RMR) was investigated using segregation analysis (POINTER) of data on families participating in Phase 2 of the Québec Family Study. Complete analyses were conducted on RMR adjusted for age, and also on RMR adjusted for age and other covariates, primarily fat mass (FM) and fat-free mass (FFM). Prior to adjustment for covariates, support for a major gene hypothesis was equivocal-i.e., there was evidence for either a major gene or a multifactorial component (i.e., polygenic and/or familial environment). The multifactorial model was preferred over the major gene model, although the latter did segregate according to Mendelian expectations. However, after the effects of FM and FFM were accounted for, a major gene effect was unambiguous and compelling. The putative locus accounted for 57% of the variance, affected 7% of the sample, and led to high values of RMR. The lack of a significant multifactorial effect suggested that the familial etiology of RMR adjusted for FM and FFM was likely to be entirely a function of the major locus. Comparing the RMR results from pre- and post-adjustment for FM and FFM suggests a plausible hypothesis. We know from earlier studies in this sample that there is a putative major gene for FM and a major non-Mendelian effect for FFM. The current study leads us to speculate that: (1) the gene(s) affecting body size and body composition also may have an effect on RMR, and further (2) removal of the effect of the major gene(s) for body size and composition allowed for detection of an additional major gene affecting only the RMR. Thus, RMR appears to be an oligogenic trait.

Overfeeding in identical twins: 5-year postoverfeeding results

From a total of 12 pairs of young male identical twins who were overfed by an estimated 84,000 kcal over a period of 100 days, several pairs (eight to 11, depending on variables) were remeasured for body weight, body composition with the underwater weighing technique, regional fat distribution from skinfolds, girths, computed tomography (CT) fat areas in the abdominal region, and fasting plasma glucose, insulin, total cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides 4 months and 5 years after completion of the overfeeding protocol. At 4 months, the twins had lost approximately 7 of 8 kg that they had gained with overfeeding. However, 5 years later, body weight had increased by 5 kg over the preoverfeeding level. Fluctuations in fat mass were greater than those in fat-free mass. The younger twins gained approximately twice as much as the older twins in the late recovery period, a difference attributed to the late phase of growth in body mass in the former. Upper-body fat was reduced at 4 months of follow-up study, but was increased in the late recovery phase. All blood values were normalized in the postoverfeeding periods. A within-pair resemblance was generally observed for the changes noted in the recovery periods, but it was more striking when variations between preoverfeeding and 4-month or 5-year values were considered. We conclude from these observations that there were no persistent effects of exposure to the overfeeding protocol over the expected age-associated increases in body mass, body fat, upper-body fat, abdominal visceral fat (AVF), and metabolic variables predictive of risk for common diseases in individuals of normal body weight and with no family history of obesity. The intrapair resemblance suggests that the genotype contributes to the alterations observed in the recovery from overfeeding and in the age-associated changes.

Plasma high-density lipoprotein cholesterol but not apolipoprotein A-I is a good correlate of the visceral obesity-insulin resistance dyslipidemic syndrome

Apolipoprotein (apo) A-I is a major component of high-density lipoproteins (HDLs), and it has been suggested that measurement of apo A-I may provide additional information in the assessment of coronary heart disease (CHD) risk. In the present study in a sample of 111 men (age [mean +/- SD], 35.3 +/- 6.6 years), we determined whether a low apo A-I concentration is associated with the cluster of metabolic abnormalities that characterize the visceral obesity-insulin resistance dyslipidemic syndrome. For this purpose, the first and fourth quartiles of apo A-I and HDL cholesterol (HDL-C) concentrations were compared in relation to body fat distribution, glucose tolerance, and plasma insulin and lipoprotein levels. Men in the first quartile (< the 25th percentile) of HDL-C, as compared with men in the fourth quartile (> the 75th percentile), were characterized by an elevated visceral adipose tissue (AT) accumulation (P < .05), as well as by increased plasma levels of triglycerides ([TGs] P < .0001), apo B (P < .0005), and insulin (P < .01). These differences were not found when the first and fourth quartiles of plasma apo A-I concentrations were compared. These results suggest that plasma levels of HDL-C are more closely associated with the various features of the visceral obesity-insulin resistance syndrome than plasma apo A-I.

Endurance exercise training has a minimal effect on resting heart rate: the HERITAGE Study

This study determined the effects of a 20-wk endurance training program (The HERITAGE Family Study) on resting heart rate (HRrest). HRrest was obtained on a sample of 26 men and 21 women during sleep; during resting metabolic rate and resting blood pressure measurement periods in the early morning following a 12-h fast and 24-h post-exercise; and at rest prior to a maximal bout of exercise. Following training, the subjects exhibited a 16.0 +/- 9.4% (mean +/- SD) increase in VO2max (P < 0.05), but the HRrest for each of the resting conditions was decreased by only 1.9 to 3.4 bpm (P < 0.05), or an average across the three conditions of 2.7 bpm. In a larger sample of 253 HERITAGE subjects, HRrest obtained only at the time of the resting blood pressure measurement decreased by only 2.6 bpm, while VO2max increased 17.7 +/- 10.0%. It is concluded that there is a significant, but small, decrease in resting heart rate as a result of 20 wk of moderate- to high-intensity endurance training; which suggests a minimal alteration in either, or both, intrinsic heart rate and autonomic control of HRrest.

Anthropometric correlates to changes in visceral adipose tissue over 7 years in women

OBJECTIVE

To investigate the association between either increases or decreases in visceral adipose tissue and changes in anthropometric indices in a group of 32 women studied over a 7-y period.

SUBJECTS

32 women aged 35.1 +/- 5.4 (SD) years at baseline.

MEASUREMENTS

Waist and hip circumferences, body fat mass (hydrostatic weighing) and viscera adipose tissue (computed tomography) were measured at baseline and at follow-up.

RESULTS

Waist girth, waist-to-hip ratio, sagittal diameter and visceral adipose tissue area were all significantly higher at follow-up than at baseline (p < 0.05). Changes in visceral adipose tissue area were strongly correlated to changes in waist girth, hip girth, sagittal diameter and body fat mass (0.80 < or = r < or = 0.91 p < 0.0001). However, the association between changes in waist-to-hip ratio and those in visceral adipose tissue area was of low magnitude (r = 0.35; p = 0.05). Partial correlation analyses showed that the association between changes in visceral adipose tissue area and changes in either waist girth (p < 0.01) or sagittal diameter (p < 0.0001) remained significant even after control for 7-y variation in total body fatness.

CONCLUSION

Results of the present study suggest that changes in visceral adipose tissue accumulation that occur with age in women are better predicted by changes in waist girth or sagittal diameter than by changes in waist-to-hip ratio.

Insulin and glucagon responses to adrenaline infusion in abdominal obese men

OBJECTIVE

To investigate the hormonal, cardiovascular and metabolic responses of visceral vs subcutaneous obese men to infused adrenaline.

DESIGN

Intervention study of an hour adrenaline infusion (0.01 micrograms/kg fat-free mass/min).

SUBJECTS

Eighteen moderately obese men (age: 30-40 y, BMI: 28-34 kg/m2) divided according to their degree (low vs high) of visceral adipose tissue (AT) accumulation.

MEASUREMENTS

Various fatness and fat distribution variables (computed tomography and anthropometry), heart rate and blood pressure, plasma concentrations of gluco-regulatory hormones, glucose, glycerol and free fatty acids (FFA).

RESULTS

Similar increases were noted in heart rate, plasma adrenaline, FFA and glycerol levels in both low and high visceral AT groups after hormonal infusion. There was a tendency for plasma glucagon responses to be higher in men with high amounts of visceral fat (p = 0.07). Plasma glucose levels increased in both groups, but significantly more in men with low levels of visceral AT (p < 0.05), whereas plasma insulin concentrations increased significantly only in men with high amounts of visceral AT in response to adrenaline infusion (p < 0.01). In the overall sample of obese men, visceral AT accumulation (but not the fat mass) was positively correlated with plasma insulin (r = 0.70) and glucagon responses (r = 0.63) to the hormone infusion (p < 0.01). These metabolic responses were not related to the achieved catecholamine concentration.

CONCLUSION

These results suggest that some of the impairments in plasma glucose-insulin homeostasis noted in visceral obesity may be related to an abnormal metabolic response to an adrenaline challenge.

Associations between health behaviours and health related fitness

OBJECTIVE

To examine relations between health behaviours and health related fitness.

METHODS

Subjects were a convenience sample of 350 healthy adults (172 men, 178 women). Covariance analysis adjusted data for significant influences of age and socioeconomic status. Obesity was assessed by anthropometry and body density. Cardiovascular fitness was assessed and various metabolic measurements were made. Questionnaires on physical activity and health related behaviours were completed.

RESULTS

Cigarette abstinence was associated with a small abdominal circumference (men) and a low trunk/extremity skinfold ratio (women). Obesity indices (body mass index, total skinfolds, percent fat, and abdominal circumference) were negatively associated with perceived fitness. Leisure activity and exercise frequency were also negatively linked to some obesity indices. Blood glucose, cholesterol, HDL-cholesterol, and triglycerides were favourably influenced by perceived activity, exercise frequency, and perceived fitness, but not by exercise intensity. Abstinence from coffee was associated with a low cholesterol/HDL ratio (men only). Principal component, discriminant, and multiple logistic regression analyses showed only weak clustering of habitual physical activity with other positive health behaviours.

CONCLUSIONS

Although multiphasic health promotion programmes are economical, favourable interactions between individual programme elements seem likely to be quite limited.