Joanna Uddén

Bioelectrical Impedance Underestimates Total and Truncal Fatness in Abdominally Obese Women

Objective: To compare estimates of total and truncal fatness from eight‐electrode bioelectrical impedance analysis equipment (BIA8) with those from DXA in centrally obese women. The secondary aim was to examine BMI and waist circumference (WC) as proxy measures for percentage total body fat (%TBF) and truncal body fat percentage (tr%BF).

No Apparent Progress in Bioelectrical Impedance Accuracy: Validation Against Metabolic Risk and DXA

Bioelectrical impedance (BIA) is quick, easy, and safe when quantifying fat and lean tissue. New BIA models (Tanita BC‐418 MA, abbreviated BIA8) can perform segmental body composition analysis, e.g., estimate %trunkal fatness (%TF). It is not known, however, whether new BIA models can detect metabolic risk factors (MRFs) better than older models (Tanita TBF‐300, abbreviated BIA4). We therefore tested the correlation between MRF and percentage whole‐body fat (%BF) from BIA4 and BIA8 and compared these with the correlation between MRF and dual‐energy X‐ray absorptiometry (DXA, used as gold standard), BMI and waist circumference (WC). The sample consisted of 136 abdominally obese (WC ≥ 88 cm), middle‐aged (30–60 years) women. MRF included fasting blood glucose and insulin; high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, and triglycerides; high sensitive C‐reactive protein, plasminogen activator inhibitor‐1 (PAI‐1), and fibrinogen; and alanine transaminase (ALT) liver enzyme. We found that similar to DXA, but in contrast to BMI, neither %BF BIA4 nor %BF BIA8 correlated with blood lipids or ALT. In the segmental analysis of %TF, BIA8 only correlated with inflammatory markers, but not insulin, blood lipids, or ALT liver enzyme (in contrast to WC and %TF DXA). %TF DXA was associated with homeostatic model assessment insulin resistance (HOMA‐IR) independently of WC (P = 0.03), whereas %TF BIA8 was not (P = 0.53). Receiver‐operating characteristic (ROC) curves confirmed that %TF BIA8 did not differ from chance in the detection of insulin resistance (P = 0.26). BIA estimates of fatness were, at best, weakly correlated with obesity‐related risk factors in abdominally obese women, even the new eight‐electrode model. Our data support the continued use of WC and BMI.

Increased physical activity in abdominally obese women through support for changed commuting habits: a randomized clinical trial.

Background:Abdominally obese women can reduce their health risk through regular physical activity. There is, however, little evidence on the effectiveness of interventions that promote physical activity long-term, such as cycling and walking to and from work.Methods:This intervention focused on physically active commuting (cycling and walking) in middle-aged (30–60 years), abdominally obese (waist circumference ⩾88 cm) women (n=120), recruited by newspaper advertisement. The intervention group was a moderate-intensity programme with physician meetings, physical activity prescriptions, group counselling and bicycles. The control group was a low-intensity group support programme with pedometers. We used a randomized, controlled, 2-armed design with 18 months duration and intention-to-treat analysis (data collection 2005–2006). Treatment success was defined as bicycling ⩾2 km/d (primary) or walking 10 000 steps per day (secondary).Results:At baseline, mean (s.d.) age was 48.2 years (7.4), waist circumference 103.8 cm (7.8), walking 8471 steps per day (2646), bicycling 0 km per day. Attrition at 18 months was 10% for the intervention group and 25% in the control group (P=0.03). The intervention group was more likely to achieve treatment success for cycling than controls: 38.7 vs 8.9% (odds ratio (OR)=7.8 (95% confidence interval=4.0 to 15.0, P<0.001)), but with no difference for compliance with the walking recommendation: 45.7 vs 39.3% (OR=1.2 (95% CI=0.7 to 2.0, P=0.50)). Commuting by car and public transport were reduced by 34% (P<0.01) and 37% (P<0.001), respectively, with no differences between groups. Both groups attained similar waist reductions (−2.1 and −2.6 cm, P=0.72).Conclusions:Abdominally obese women can increase PA long-term through moderate-intensity behavioural support aimed at changing commuting habits.

Impact of physical activity and body composition on heart function and morphology in middle-aged, abdominally obese women

Several studies have shown training induced morphological changes in the heart. Our aim was to assess how frequent, low‐intensity exercise (walking and cycling) influences heart function and morphology in abdominally obese women. Fifty women with abdominal obesity (mean age 47·0 ± 7·5 years, waist circumference (WC) 103·2 ± 7·8 cm), free of cardiovascular problems were recruited. They were equipped with a bicycle and pedometers and instructed to start commuting in a physically active way for 6 months. Evaluation of cardiac function and morphology was performed using echocardiography (ECHO) before and after 6 months of training. The subjects increased significantly their daily physical activity. After 6 months, there was a significant decrease in WC (from 103·3 ± 7·9 to 100·8 ± 8·4 cm, P = 0·0003), in systolic and diastolic blood pressure (126·8 ± 15·2 to 120·4 ± 14·5 mmHg, P = 0·0001, and 79·8 ± 7·8 to 77·8 ± 8·4 mmHg, P = 0·0006, respectively). ECHO showed an increase in the right ventricular (RV) systolic longitudinal function expressed as tricuspid annular motion from 22·00 ± 3·30 to 23·05 ± 3·59 mm, P = 0·015; and a similar trend in left ventricular (LV) mitral annular motion, which increased from 13·09 ± 1·53 to 13·39 ± 1·47 mm, P = 0·070. Cycling was associated with reductions in LV systolic and RV diastolic dimensions, whereas walking was not associated with any changes in the ECHO‐variables. A reduction in WC by frequent, low‐intensity exercise in abdominally obese women is associated with decrease in blood pressure and improved longitudinal RV systolic function.

Weight reduction improves sleep, sleepiness and metabolic status in obese sleep apnoea patients

SUMMARY METHOD In this prospective intervention study, 33 obese patients with obstructive sleep apnoea syndrome (OSAS) (24 men, 9 women) were consecutively enrolled for a weight reduction program at the Obesity Unit, Karolinska University Hospital. 23 of 33 patients used OSAS-device, 19 with Continuous Positive Airway Pressure and 4 with Mandibular Retaining Device. The patients were investigated with questionnaires, blood tests and ambulant nocturnal polysomnography before and after a 6-month program. Patients with OSAS-device slept without it during the sleep studies. The intervention consisted of 8 weeks low calorie diet and group meetings, followed by a day-care program of behaviour change support. RESULTS 27 of 33 patients (82%, 21 men and 6 women) completed the study. After the intervention there were highly significant decreases (p < 0.001) in Body Mass Index from mean(S.D.) 40(5) to 34(3), apnoea-hypopnoea index from 43(24) to 26(20) and Epworth Sleepiness Scale (ESS)-score from 9(4) to 6(4). Sleep quality (arousal index, sleep efficiency, percentage deep sleep) and metabolic status (blood pressure, blood glucose levels, lipidemia) were also significantly improved. There was a significant correlation between increased percentage deep sleep and reduced ESS-score. There were no differences due to gender or use/no use of OSAS-device. CONCLUSION The results suggest that weight loss, induced by low calorie diet and behaviour change support, significantly improves nocturnal respiratory parameters, sleep quality, daytime sleepiness and metabolic status in obese OSAS patients after 6 months.