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Biomedical subjects

M E Lean

Publications and source records attributed to M E Lean.

At least 73 records · Page 4Linked to original sources
PubMed1997

The prevalence of low back pain and associations with body fatness, fat distribution and height.

OBJECTIVES: To examine the associations of low back pain symptoms with waist circumference, height, waist to hip ratio and body mass index, and to test the interactions between (1) waist circumference and height, and (2) waist to hip ratio and body mass index. SETTING: Cross-sectional study set in The Netherlands of a random sample of 5887 men and 7018 women aged 20-60 y. RESULTS: The prevalences of low back pain in men and women in the past 12 months were 46% and 52%, of whom 17% and 21% had low back pain for a total of 12 or more weeks, and 13% and 18% had symptoms suggestive of intervertebral disc herniation. After adjustments for age, smoking and education, more women in the highest tertile of waist circumference reported low back pain in the past 12 months (odds ratio = 1.2, 95% confidence interval: 1.1-1.4), low back pain for a total of 12 or more weeks (odds ratio = 1.5, 95% confidence interval: 1.3-1.8), and intervertebral disc herniation symptoms (odds ratio = 1.3, 95% confidence interval: 1.1-1.6) than women in the lowest waist tertile. Corresponding values of low back pain symptoms for women with high body mass index or high waist to hip ratio were similar to those with high waist. There were no significant differences between men in different tertiles of waist, waist to hip ratio or body mass index reporting low back pain symptoms. Tallest subjects did not report low back pain symptoms more often than shortest subjects. There was no significant interactions between waist and height or between waist to hip ratio and body mass index on low back pain symptoms. CONCLUSIONS: Women who are overweight or with a large waist have a significantly increased likelihood of low back pain. There are no significant interactions between waist and height, or waist to hip ratio and body mass index on low back pain symptoms.

Adipose Tissue↗
PubMed1997

Moderate weight reduction improves red cell aggregation and factor VII activity in overweight subjects.

OBJECTIVE: To investigate the effect of a dietary intervention to reduce body weight on red cell aggregation (RCA), factor VII activity, plasminogen activator inhibitor (PAI) activity, tissue plasminogen activator (t-PA) antigen, fibrinogen, whole blood and plasma viscosity, haematocrit and lipids. DESIGN: Open single stranded study of dietary intervention for weight loss in a volunteer sample. SUBJECTS: Forty-five subjects whose BMI exceeded 26 kg/m2 were recruited and received dietetic advice designed to reduce body weight by 0.5 kg per week. MEASUREMENTS: Body weight and waist and hip circumferences, dietary intake by seven day weighed inventory, RCA, factor VII activity, PAI activity, t-PA antigen, fibrinogen, whole blood and plasma viscosity, haematocrit and lipids. RESULTS: After 12 weeks of dietary intervention there were reductions in body weight and BMI by 5.9 (s.d. 3.3) kg and 1.9 (s.d. 1.0) kg/m2 respectively in males, and 4.1 (s.d. 2.9) kg and 1.6 (s.d. 1.1) kg/m2 in females (P < 0.0001). Factor VII activity (P = 0.0043), RCA (P = 0.01) and t-PA antigen (P = 0.016) were reduced in females after weight reduction but no differences were found in PAI activity, whole blood, plasma viscosity or haematocrit. The changes in factor VII activity and RCA were appropriate for the changes in BMI on the basis of the relationships of the risk factors with BMI in a cross sectional survey of a representative Scottish population. Plasma total cholesterol was reduced (P = 0.016) but HDL cholesterol and triglycerides remained unchanged. There were significant associations between the reductions in factor VII activity and BMI (r = 0.395, P = 0.013) and between the reductions in RCA and waist to hip ratio (r = 0.350, P = 0.04). No relationship was seen between changes in serum cholesterol and changes in factor VII activity or RCA. CONCLUSIONS: Modest weight loss, of 5% body weight, with conventional dietary intervention reduces two established risk factors for ischaemic heart disease (factor VII activity and RCA) which are generally elevated in those with increased body weight.

Adult↗
PubMed1997

Relationship between volumes and areas from single transverse scans of intra-abdominal fat measured by magnetic resonance imaging.

OBJECTIVE: To determine the level of a single transverse scan of intra-abdominal fat between L1 and L5 vertebrae that best predicts intra-abdominal fat volumes. SUBJECTS: Sixteen male and seven female patients with non-insulin-dependent diabetes mellitus, aged 44-74 y. OUTCOME MEASURES: Volumes and areas from single scans of intra-abdominal fat measured by magnetic resonance imaging with a 1.5 Tesla magnetic field strength. RESULTS: Intra-abdominal fat volumes and were calculated from fat areas from eight cross-sectional transverse single scans (nine scans in eight men) of 20 mm thickness. Men and women, respectively, had mean body mass index (BMI) of 27.9 (s.d. 3.0) and 31.6 (s.d. 4.7) kg/m2, and intra-abdominal fat of 2.3 (s.d. 0.5) and 2.5 (s.d. 0.6) kg. Intra-abdominal fat area of the fourth scan (in the direction of L1 to L5) gave the highest prediction of total intra-abdominal fat both in men (r = 0.959, P < 0.001) and in women (r = 0.973, P < 0.001). The intra-abdominal fat area of the third scan gave almost as good a prediction. These third and fourth scans corresponded to L2 and L3 vertebrae. The intra-abdominal fat areas from the sixth and seventh scans, corresponded to the frequently used L4-L5 and had lower correlations with intra-abdominal fat. There were no gender differences in the prediction of volumes from areas of intra-abdominal fat. Intra-abdominal fat areas of the fourth scan explained 93% of variance (SEE = 0.14 kg) of total of intra-abdominal fat for both genders: intra-abdominal fat (kg) = 0.0108 x intra-abdominal fat area of the fourth scan (cm2) + 0.244. CONCLUSIONS: In large studies of intra-abdominal fat, using magnetic resonance imaging (MRI) or computerised tomography scanning, a single intra-abdominal fat area at the intervertebral disc between L-2 and L-3 vertebrae offers a cheaper, faster and safer method, with high prediction of total intra-abdominal fat volumes and masses.

Abdomen↗
PubMed1997

Narrow hips and broad waist circumferences independently contribute to increased risk of non-insulin-dependent diabetes mellitus.

OBJECTIVES: Patients with non-insulin-dependent diabetes mellitus (NIDDM) have been shown to be more obese and have higher waist-to-hips circumference ratios compared to nondiabetics. In this study, we tried to dissociate obesity, waist and hip circumference from NIDDM. DESIGN: A cross-sectional population-based case-control study. SETTING: General population. SUBJECTS CONTROLS: 5887 men and 7018 women, aged 20-59 years, without known diabetes or hyperglycaemia. CASES: 93 men and 66 women were diagnosed with NIDDM. MAIN OUTCOME MEASURES: We predicted waist and hips' circumference from the body mass index, weight/height2, (BMI) on the basis of linear regression. Differences between observed and expected values (residuals) of waist and hip circumference were categorized into tertiles. The relative odds of having NIDDM in tertiles of waist and hip residuals (middle tertile as reference) were calculated by multiple logistic regression analysis adjusted for each other and for age, smoking, physical activity, alcohol consumption and education. RESULTS: NIDDM was most prevalent in men and women who had larger waists and in those who had smaller hip circumferences than expected from their BMI. Adjusted odds ratios (95% CI) for NIDDM were 2.9 (1.6-5.1) in men and 2.8 (1.5-5.1) in women who had a larger than expected waist, and were 3.7 (2.1-6.5) in men and 2.1 (1.1-3.8) in women who had smaller than expected hips. CONCLUSIONS: Our findings suggest that diabetics have larger waists and smaller hips compared to nondiabetics, irrespective of their degree of obesity, age and life-style factors. One possibility is that besides abdominal fatness, peripheral muscle atrophy is one of the factors associated with NIDDM.

Abdomen↗
PubMed1997

Effect of inflammation on measures of antioxidant status in patients with non-small cell lung cancer.

This study examined the effect of an inflammatory response on measures of antioxidant status in patients with non-small cell lung cancer (NSCLC). In healthy, control subjects (n = 13) and NSCLC patients (n = 22) fasting concentrations of albumin, C-reactive protein, cholesterol, and the antioxidants alpha-tocopherol, retinol, lutein, lycopene, and alpha- and beta-carotene were measured. The two groups were similar in terms of age, sex, and body mass index. However, the cancer group had an inflammatory response as evidenced by significantly increased C-reactive protein concentrations. Concentrations of all the measured antioxidants of the NSCLC group were significantly lower than those of the control group (P < 0.01). The lowest concentrations were those of the carotenoids lycopene and alpha- and beta-carotene. In the cancer group there were significant negative correlations between concentrations of C-reactive protein and retinol (r = -0.682, P < 0.01), alpha-tocopherol (r = -0.464, P < 0.05), and lutein (r = -0.599, P < 0.01). The results of this study have implications for the interpretation of circulating antioxidant concentrations in patients with NSCLC.

Aged↗
PubMed1997

Sibutramine--a review of clinical efficacy.

Controlled studies have shown that sibutramine produces dose-related weight loss when given in the range 5-30 mg per day, with optimal doses of 10 and 15 mg per day. Weight loss with sibutramine is 3-5 kg better than placebo at 24 weeks, and weight loss is maintained to 52 weeks at doses of 10 and 15 mg. By six months, 69% of patients treated with sibutramine 15 mg achieve a 5% or greater reduction in their baseline weight. The weight loss achieved with sibutramine was similar to that achieved with dexfenfluramine over 12 weeks (4.5 kg compared with 3.2 kg). Sibutramine-induced weight loss has been found to be accompanied by a significant reduction in waist/hip ratio, and decreases in plasma triglycerides, total cholesterol and low density lipoprotein (LDL) cholesterol. There were also increases in high density lipoprotein (HDL) cholesterol. In patients with type II diabetes, sibutramine-induced weight loss was accompanied by a shift towards improved glycaemic control. In controlled studies, 84% of sibutramine-treated patients reported adverse events, compared with 71% of patients receiving placebo. The most frequently reported adverse events are related to pharmacological actions of sibutramine, and include dry mouth, decreased appetite, constipation and insomnia.

Anti-Obesity Agents↗
PubMed1996

Waist circumference as a screening tool for cardiovascular risk factors: evaluation of receiver operating characteristics (ROC).

UNLABELLED: To evaluate the receiver operating characteristics (ROC) to determine the cutoffs of waist circumference as a potential population directed screening tool for hypercholesterolaemia (> or = 6.5 mmol/L), low high density lipoprotein cholesterol (< 0.9 mmol/L), and hypertension (treated and/or systolic > or = 160 and/or diastolic blood pressure > or = 95 mmHg), in 2183 men and 2698 women aged 20 to 59 years selected at random from Dutch civil registries. MAIN OUTCOME MEASURES: Height, weight, body mass index (BMI), waist circumference, total plasma cholesterol and high density lipoprotein cholesterol concentrations, and blood pressure. RESULTS: ROC curves showed that sensitivity equalled specificity at waist circumferences between 93-95 cm in men and 81-84 cm in women for identifying individual risk factors, and 92 cm in men and 81 cm in women for identifying those with at least one risk factor. Sensitivity and specificity were equal at levels between 61% to 69% for identifying individual risk factors, with positive predictions (56.8% in men and 37.8% in women) within 2% of those using previously defined 'Action Level 1' of waist circumference 94 cm in men and 80 cm in women (58.8% in men and 37.4% in women). Risk prediction by anthropometric methods was relatively low: ROC areas for identifying each risk factor by waist varied from 55% to 60%, and reached about 65% for identifying at least one risk factor. Height accounted for less than 0.3% of variance in waist circumference. Using BMI at 25 kg/m2 gave similar prediction to waist, but its combination with waist did not improve predictive values. CONCLUSIONS: Measurement of waist circumference 'Action Level 1' at 94 cm (37 inches) in men and 80 cm (32 inches) in women could be adopted as a simpler valid alternative to BMI for health promotion, to alert those at risk of cardiovascular disease, and as a guide to risk avoidance by self-weight management.

Adult↗
PubMed1996

The influence of dietary folate and methionine on the metabolic disposition of endotoxic homocysteine.

We have investigated the disposition of potentially endotoxic homocysteine (Hcy) and its transsulfuration metabolite cysteine (Cys) in 98 individuals (age range 20-66 years). Our study reports on the relationship between Hcy and two important dietary factors likely to influence plasma levels of this thiol: dietary folate and dietary methionine. chi2 analysis shows a low frequency of elevated plasma Hcy at high folate intake. This frequency for Hcy >10 micromol/liter with a folate intake >350 microg/day is significant (P < 0.02). The data reflect a tendency for elevated Hcy values to be associated with low dietary folate, although many subjects with a low dietary folate also had a low plasma Hcy. Intake of dietary methionine was found to be significantly higher in males than in females (P < .0001). This may account for the looser relationship between Hcy and its transsulfuration product, Cys, in females (R2 = 0.30) compared to males (R2 = 0.73), since conversion of methionine to SAM in males would activate cystathionine beta synthase and commit excess Hcy to transsulfuration. The generally lower methionine intake of females means that more Hcy is utilized in the remethylation cycle in which methionine is produced from the de novo methyl group of 5-methyltetrahydrofolate or from the preformed methyl group of betaine. Clearly a Hcy moiety locked up in remethylation would be further removed from Cys, the end product of transsulfuration. An increasing number of studies are clarifying the relationship between Hcy, folate, and other B vitamins. However, less attention seems to be given to the influence of dietary methionine on the disposition of Hcy. The present study supports biochemical theory and indicates that more focus should be given to the effect of dietary methionine on Hcy. These findings have particular significance since even moderate increases in plasma Hcy are associated with a toxic vascular effect. Consequently the relationship between dietary folate and Hcy levels should be a factor in evaluating recommended dietary allowances for this vitamin. The simplicity of our dietary folate questionnaire also raises the possibility of a screening test in which individuals can ascertain whether their folate intake is adequate to reduce Hcy levels to a benign value.

Adolescent↗
PubMed1996

Predicting body composition by densitometry from simple anthropometric measurements.

New equations have been developed to predict body fat (percent BF) calculated from body density measured by underwater weighing from simple anthropometric measurements, using stepwise-multiple-regression analysis in 63 men and 84 women. Log10 sum of four skinfold thickness explained 80.1% (SE = 3.8) of variance of percent BF in men and 76.4% (SE = 4.6) in women. Alternative equations using limb lengths instead of height may be valuable for epidemiologic and clinical work, with particular advantages for the chair- or bed bound, for whom no previous predictive equations existed. Five equations combining triceps-skinfold thickness with other anthropometric measurements explained > 80% (men) and 77% (women) of variance. The most powerful prediction was from waist circumference and triceps-skinfold thickness, which explained 86.6% (SE = 3.2) of variance of percent BF in men and 79.0% (SE = 4.0) in women. Percent BF for men = 0.353 waist (cm) + 0.756 triceps (mm) + 0.235 age (y) - 26.4; for women = 0.232 waist (cm) + 0.657 triceps (mm) + 0.215 age (y) - 5.5. The equations were tested in a separately studied validation sample of 146 men and 238 women aged 18-83 y. Skinfold-thickness measurements continued to give good predictions of mean body density, but with significant bias at extremes of body fat and age. The most robust prediction with the least bias was from waist circumference adjusted for age. Percent BF for men = 0.567 waist (cm) + 0.101 age (y) - 31.8; and for women = 0.439 waist (cm) + 0.221 age (y) - 9.4.

Adipose Tissue↗
PubMed1996

Abnormal antioxidant vitamin and carotenoid status in chronic renal failure.

Oxidative modification of plasma lipoproteins increases their atherogenicity. Nutritive antioxidants, including carotenoids, can prevent such lipoperoxidation and may protect against atherosclerosis. Plasma retinol, ascorbate, alpha-tocopherol and four carotenoids (lutein, lycopene, alpha-carotene and beta-carotene) were measured using HPLC in 45 patients with chronic renal failure (CRF) and in 21 controls. Plasma retinol was significantly increased in patients with CRF (conservative therapy mean of 3.7 mumol/l vs. 1.9 mumol/l; p < 0.001). Plasma lycopene was significantly lower in patients with CRF (healthy mean 0.44 mumol/l vs. conservative therapy mean 0.27 mumol/l and haemodialysis mean of 0.17 mumol/l; p < 0.001), a finding that persisted even after adjusting for plasma cholesterol. Low circulating antioxidant lycopene levels may contribute to an already impaired antioxidant defence system in patients with CRF. The process of haemodialysis further compromises antioxidant defences, principally by removing water-soluble ascorbate and urate, but does not appear to affect circulating carotenoid concentrations.

Adult↗
PubMed1996

Lower leg length as an index of stature in adults.

OBJECTIVE: To derive regression equations using lower leg length (knee height) or arm span to predict height, and equations using ratios of weight/lower leg length or weight/arm span to predict body mass index and % body fat. SUBJECTS: Determination sample of 78 men and 82 women aged 17-70 years, and validation sample of 53 men and 121 women aged 18-82 years. MEASUREMENTS: Height, weight, lower leg length measured from the top of the patella with knee flexed at 90 degrees, arm span, % body fat by densitometry, and age. RESULTS: Lower leg length gave good prediction of height (men: r2 = 79%, SEE = 3.2 cm; women: r2 = 73%, SEE = 3.4 cm). Weight/lower leg length ratio was highly predictive of body mass index (men: r2 = 95%, SEE = 1.1 kg/m2, women: r2 = 94%, SEE = 1.1 kg/m2), and gave an estimation comparable to that of body mass index for predicting % body fat (men: r200 = 68%, SEE = 5.0% of body weight; women: r2 = 72%, SEE = 4.6% of body weight). Applying these equations based on lower leg length and weight/lower leg length ratio to a separate sample of men and women showed 95% of the errors of height estimate were within 6.5 cm, and of body mass index estimate were within 2 kg/m2. The same analysis of arm span showed the errors of body composition prediction were unacceptably high. CONCLUSION: Lower leg length is useful for estimating body composition when height measurement is not available.

Adolescent↗
PubMed1996

The influence of fat free mass on prediction of densitometric body composition by bioelectrical impedance analysis and by anthropometry.

OBJECTIVE: To examine the effect of varying size of fat free mass (FFM) on the precision and bias of body composition prediction by bioelectrical impedance analysis (BIA) from four equations of Segal et al (BIA-Segal), Gray et al (BIA-Gray, Lukaski et al (BIA-Lukaski) and those from a manufacturer (BIA-EZC), by body mass index (BMI), and by skinfold methods with reference to estimation by densitometry. SUBJECTS: 73 men and 77 women aged 17-71 years, were measured for height, weight, FFM, bioelectrical impedance and age. RESULTS: BIA-Segal gave the highest precision (men: R2 = 83%, women: R2 = 75%) and the least bias (men: slope = 0.88; women: slope = 0.81) of all BIA methods. There were poorer precision (R2 < or = 50%) and more bias (slope < 0.70) by BIA-Lukaski and BIA-EZC in both sexes, which were comparable to the simpler BMI method. The skinfold method gave R2 = 83% and slope = 0.84 in men and R2 = 61% and slope = 0.86 in women. Bland and Altman analysis showed BIA-Segal gave prediction of FFM within +/-6 kg of 95% confidence interval limit of agreement of that estimated by UWW in most subjects. Other BIA methods presented unacceptably large underestimates of up to 15-17 kg in FFM. CONCLUSIONS: The BIA-Segal provide the best predictions of the methods tested, but using BMI-or waist-specific equations may be more practical than the original BIA-Segal method, which BIA methods are affected by large FFM, and not better than anthropometric methods in predicting FFM.

Adolescent↗
PubMed1995

Waist circumference action levels in the identification of cardiovascular risk factors: prevalence study in a random sample.

OBJECTIVE: To determine the frequency of cardiovascular risk factors in people categorised by previously defined "action levels" of waist circumference. DESIGN: Prevalence study in a random population sample. SETTING: Netherlands. SUBJECTS: 2183 men and 2698 women aged 20-59 years selected at random from the civil registry of Amsterdam and Maastricht. MAIN OUTCOME MEASURES: Waist circumference, waist to hip ratio, body mass index (weight (kg)/height (m2)), total plasma cholesterol concentration, high density lipoprotein cholesterol concentration, blood pressure, age, and lifestyle. RESULTS: A waist circumference exceeding 94 cm in men and 80 cm in women correctly identified subjects with body mass index of > or = 25 and waist to hip ratios > or = 0.95 in men and > or = 0.80 in women with a sensitivity and specificity of > or = 96%. Men and women with at least one cardiovascular risk factor (total cholesterol > or = 6.5 mmol/l, high density lipoprotein cholesterol < or = 0.9 mmol/l, systolic blood pressure > or = 160 mm Hg, diastolic blood pressure > or = 95 mm Hg) were identified with sensitivities of 57% and 67% and specificities of 72% and 62% respectively. Compared with those with waist measurements below action levels, age and lifestyle adjusted odds ratios for having at least one risk factor were 2.2 (95% confidence interval 1.8 to 2.8) in men with a waist measurement of 94-102 cm and 1.6 (1.3 to 2.1) in women with a waist measurement of 80-88 cm. In men and women with larger waist measurements these age and lifestyle adjusted odds ratios were 4.6 (3.5 to 6.0) and 2.6 (2.0 to 3.2) respectively. CONCLUSIONS: Larger waist circumference identifies people at increased cardiovascular risks.

Adult↗
PubMed1995

Waist circumference as a measure for indicating need for weight management.

OBJECTIVE: To test the hypothesis that a single measurement, waist circumference, might be used to identify people at health risk both from being overweight and from having a central fat distribution. DESIGN: A community derived random sample of men and women and a second, validation sample. SETTING: North Glasgow. SUBJECT: 904 men and 1014 women (first sample); 86 men and 202 women (validation sample). MAIN OUTCOME MEASURES: Waist circumference, body mass index, waist:hip ratio. RESULTS: Waist circumference > or = 94 cm for men and > or = 80 cm for women identified subjects with high body mass index (> or = 25 kg/m2) and those with lower body mass index but high waist:hip ratio (> or = 0.95 for men, > or = 0.80 women) with a sensitivity of > 96% and specificity > 97.5%. Waist circumference > or = 102 cm for men or > or = 88 cm for women identified subjects with body mass index > or = 30 and those with lower body mass index but high waist:hip ratio with a sensitivity of > 96% and specificity > 98%, with only about 2% of the sample being misclassified. CONCLUSIONS: Waist circumference could be used in health promotion programmes to identify individuals who should seek and be offered weight management. Men with waist circumference > or = 94 cm and women with waist circumference > or = 80 cm should gain no further weight; men with waist circumference > or = 102 cm and women with waist circumference > or = 88 cm should reduce their weight.

Adult↗