Background Evidence on the incidence and risk factors for lower limb lymphedema (LLL) associated ... more Background Evidence on the incidence and risk factors for lower limb lymphedema (LLL) associated with endometrial cancer is limited. Our objective was to use data from a prospective, longitudinal gynaecological cancer cohort study to determine LLL incidence up to 24 months post-diagnosis of endometrial cancer and to explore the relationship between personal and treatment-related factors and risk of developing LLL. Methods Women recently diagnosed with endometrial cancer (n=235) were evaluated at regular intervals postdiagnosis (up to 3-monthly) using bioimpedance spectroscopy (BIS) and self-reported leg swelling (SRLS). Results Incidence of LLL at 24 months post-diagnosis was 33% and 45% according to BIS and SRLS, respectively. When analyses were restricted to obese women, incidence at 24 months post-diagnosis increased to 67% (BIS) and 54% (SRLS). Following adjusted analyses, higher body mass index was associated with higher odds of baseline lymphedema (BIS:
A better understanding of the pathophysiology of pediatric postthrombotic syndrome (PTS) is neede... more A better understanding of the pathophysiology of pediatric postthrombotic syndrome (PTS) is needed to develop strategies to treat this condition. We investigated calf pump function, exercise capacity, balance in power output, and changes in limb muscle oxygen saturation (SmO2) and fluid content during exercise in 10 pediatric patients with unilateral lower-limb PTS, and in age- and sex-matched controls (1:1-1:2 ratio). Outcomes were investigated using bioimpedance spectroscopy, torque-sensing pedals, and near-infrared spectroscopy during incremental- and constant-load cycling tests. The median age at participation was 17 years (25th-75th percentile, 15-18 years); 68% of participants were females. The median CAPTSure score in the affected leg of affected participants was 35 points (25th-75th percentile, 24-46 points), indicating moderate/severe PTS; 20% of patients had a history of central venous catheter–related thrombosis. Increasing PTS severity was associated with higher calf pum...
Background: Bioimpedance spectroscopy (BIS) devices are routinely used in the assessment of breas... more Background: Bioimpedance spectroscopy (BIS) devices are routinely used in the assessment of breast cancer-related lymphedema (BCRL). The equipotential electrode placement is a commonly used protocol for the assessment of BCRL. However, the sternal notch electrode placement protocol is also in use. Whether these two protocols are interchangeable is not known. Methods and Results: Ethical approval was received from the institutional ethics committee at Tata Memorial Hospital, India. BIS measurements (whole-body right side and affected and unaffected arms) of 100 women with or at risk of BCRL were measured using equipotential and sternal notch protocols. Resistance at zero frequency (R0) was determined, and agreement of the absolute R0 values and the R0 ratio (unaffected/affected) between protocols was evaluated (Bland-Altman analysis and Passing-Bablok regression analysis). Mean absolute differences between protocols were very small for whole-body right side, affected arm, unaffected arm, and the interarm ratio at 0.23 ohms (95% confidence interval [CI]: -3.8 to 4.3), -5.7 ohms (95% CI: -7.5 to -3.9), -9.09 ohms (95% CI: -11.4 to -6.8), and -0.008 ohms (95% CI: -0.02 to 0.001), respectively. Limits of agreement (two standard deviation) between protocols were narrow for whole-body right side, affected arm, unaffected arm, and interarm ratio without any systematic or proportional differences for whole-body right side and the interarm ratio (5.8% to -5.6%, 3.7% to -7.4%, 3.5% to -8.2%, and 5.8% to -5.6%, respectively). Conclusion: The equipotential and sternal notch protocols could be used interchangeably in BCRL assessment. The Clinical Trial Registration number: CTRI/2017/12/010762.
Doubly labelled water (DLW) is considered the criterion method for assessment of total energy exp... more Doubly labelled water (DLW) is considered the criterion method for assessment of total energy expenditure (TEE) and physical activity energy expenditure (PAEE) under free-living conditions; however, it is costly and requires significant technical expertise. Body-worn physical activity monitors are a good proxy for estimating TEE and PAEE, but their accuracy compared to DLW remains uncertain in older women. PURPOSE: This study sought to i) validate three physical activity (PA) monitors for TEE assessment in free-living older women using DLW as the criterion method and ii) determine the accuracy of the PAEE estimates obtained by these monitors. METHODS: Thirty three women (age 60.7 ± 7.1 y; mean BMI 26.9 ± 5.0 kg•m) were recruited for this study. TEE and PAEE were measured over a 14-day period using a standardised protocol for DLW (H2O and H2 O). Women also wore SenseWear armband (SAB), ActiHeartTM (AH) and ActiGraph GT3X (AG) PA monitors continuously, and at the same time, during their waking hours over 7 d, except for water-based activities such as bathing or swimming. RESULTS: Paired t-tests revealed mean differences of -163 ± 307 kcal•d between TEEDLW and TEESAB; -134 ± 279 kcal•d -1 between TEEDLW and TEEAH; and -143 ± 242 kcal•d -1 between TEEDLW and TEEAG (all p<0.05). Measurements from PA monitors underestimated TEE derived from the criterion DLW by 6%-7%. The agreement between the criterion and PA devices for TEE demonstrated concordance (ρc) from 0.51 to 0.75. TEEDLW was strongly correlated with TEEAG (r=0.80; p<0.05). PAEE derived from PA monitors significantly underestimated the criterion PAEE by 18%-68%, with mean differences of -332 ± 333 kcal•d between PAEEDLW and PAEESAB, -124 ± 250 kcal•d -1 between PAEEDLW and PAEEAH and -130 ± 217 kcal•d -1 between PAEEDLW and PAEEAG (all p<0.05). There was a moderate correlation between PAEEDLW and PAEEAG (r=0.61; p<0.05), but ρc was non-existent to moderate, ranging from 0.00 to 0.53. CONCLUSION: There were good levels of agreement between body-worn physical activity monitors and a criterion measurement of TEE in older women under free-living conditions. Physical activity monitors consistently underestimated daily levels of energy expenditure, although agreement with a criterion method was better for estimating TEE, than for PAEE. More work is needed to improve the ability of these PA monitors to accurately measure energy expenditure during daily physical activities.
Proceedings of the 2nd International Conference on Bioelectromagnetism (Cat. No.98TH8269), 1998
A novel method utilising both tetrapolar and bipolar impedance analysis was developed for the mea... more A novel method utilising both tetrapolar and bipolar impedance analysis was developed for the measurement of the impedance of skin and underlying subcutaneous tissue. Impedance and skin-fold thickness were measured at four sites (biceps, triceps, subscapular and suprailiac) conventionally used for measurement of skin-folds and estimation of total body fat. Impedance was highly and significantly correlated (r=0.80 to 0.94) with
Chronic treatment of male Wistar rats with ethanol (15% v/v) in drinking fluid for a period of 3 ... more Chronic treatment of male Wistar rats with ethanol (15% v/v) in drinking fluid for a period of 3 months affected the binding of the chloride channel antagonist, [(35)S]TBPS, to well-washed synaptic membranes and slide-mounted brain slices, the affinity for [(35)S]TBPS in brains of ethanol-treated animals was significantly decreased in comparison to controls while receptor density was increased (P &lt; 0.001). However, other well described treatments, viz. an ethanol-containing liquid diet and chronic inhalation of ethanol failed to demonstrate changes in the binding of [(35)S]TBPS in brain preparations. Our findings suggest that long-term administration of ethanol can induce alterations in the characteristics of the ionophore component of the GABA-benzodiazepine receptor complex. This may have relevance to ethanol-induced neuronal damage.
ABSTRACT Lymphoedema is a chronic debilitating condition that may occur in approximately 25% of w... more ABSTRACT Lymphoedema is a chronic debilitating condition that may occur in approximately 25% of women treated for breast cancer. As the condition progresses, accumulated lymph fluid becomes fibrotic with infiltration of adipose tissue. Bioelectrical impedance spectroscopy is the preferred method for early detection of lymphoedema based on the measurement of impedance of extracellular fluid. The present study assessed whether these impedance measurements could also be used to estimate the adipose tissue content of the arm based on a model previously used to predict whole body composition. Estimates of arm adipose tissue in a cohort of women with lymphoedema were found to be highly correlated (r &gt; 0.82) with measurements of adipose tissue obtained using the reference method of dual energy X-ray absorptiometry. Paired t-tests confirmed that there was no significant difference between the adipose tissue volumes obtained by the two methods. These results support the view that the method shows promise for the estimation of arm adiposity in lymphoedema.
SummaryBioelectrical impedance analysis (BIA) is a practical method to estimate percentage body f... more SummaryBioelectrical impedance analysis (BIA) is a practical method to estimate percentage body fat (%BF). In this systematic review, we aimed to assess validity, responsiveness, reliability and measurement error of BIA methods in estimating %BF in children and adolescents.We searched for relevant studies in Pubmed, Embase and Cochrane through November 2012. Two reviewers independently screened titles and abstracts for inclusion, extracted data and rated methodological quality of the included studies. We performed a best evidence synthesis to synthesize the results, thereby excluding studies of poor quality. We included 50 published studies. Mean differences between BIA and reference methods (gold standard [criterion validity] and convergent measures of body composition [convergent validity]) were considerable and ranged from negative to positive values, resulting in conflicting evidence for criterion validity. We found strong evidence for a good reliability, i.e. (intra‐class) corr...
Background Evidence on the incidence and risk factors for lower limb lymphedema (LLL) associated ... more Background Evidence on the incidence and risk factors for lower limb lymphedema (LLL) associated with endometrial cancer is limited. Our objective was to use data from a prospective, longitudinal gynaecological cancer cohort study to determine LLL incidence up to 24 months post-diagnosis of endometrial cancer and to explore the relationship between personal and treatment-related factors and risk of developing LLL. Methods Women recently diagnosed with endometrial cancer (n=235) were evaluated at regular intervals postdiagnosis (up to 3-monthly) using bioimpedance spectroscopy (BIS) and self-reported leg swelling (SRLS). Results Incidence of LLL at 24 months post-diagnosis was 33% and 45% according to BIS and SRLS, respectively. When analyses were restricted to obese women, incidence at 24 months post-diagnosis increased to 67% (BIS) and 54% (SRLS). Following adjusted analyses, higher body mass index was associated with higher odds of baseline lymphedema (BIS:
A better understanding of the pathophysiology of pediatric postthrombotic syndrome (PTS) is neede... more A better understanding of the pathophysiology of pediatric postthrombotic syndrome (PTS) is needed to develop strategies to treat this condition. We investigated calf pump function, exercise capacity, balance in power output, and changes in limb muscle oxygen saturation (SmO2) and fluid content during exercise in 10 pediatric patients with unilateral lower-limb PTS, and in age- and sex-matched controls (1:1-1:2 ratio). Outcomes were investigated using bioimpedance spectroscopy, torque-sensing pedals, and near-infrared spectroscopy during incremental- and constant-load cycling tests. The median age at participation was 17 years (25th-75th percentile, 15-18 years); 68% of participants were females. The median CAPTSure score in the affected leg of affected participants was 35 points (25th-75th percentile, 24-46 points), indicating moderate/severe PTS; 20% of patients had a history of central venous catheter–related thrombosis. Increasing PTS severity was associated with higher calf pum...
Background: Bioimpedance spectroscopy (BIS) devices are routinely used in the assessment of breas... more Background: Bioimpedance spectroscopy (BIS) devices are routinely used in the assessment of breast cancer-related lymphedema (BCRL). The equipotential electrode placement is a commonly used protocol for the assessment of BCRL. However, the sternal notch electrode placement protocol is also in use. Whether these two protocols are interchangeable is not known. Methods and Results: Ethical approval was received from the institutional ethics committee at Tata Memorial Hospital, India. BIS measurements (whole-body right side and affected and unaffected arms) of 100 women with or at risk of BCRL were measured using equipotential and sternal notch protocols. Resistance at zero frequency (R0) was determined, and agreement of the absolute R0 values and the R0 ratio (unaffected/affected) between protocols was evaluated (Bland-Altman analysis and Passing-Bablok regression analysis). Mean absolute differences between protocols were very small for whole-body right side, affected arm, unaffected arm, and the interarm ratio at 0.23 ohms (95% confidence interval [CI]: -3.8 to 4.3), -5.7 ohms (95% CI: -7.5 to -3.9), -9.09 ohms (95% CI: -11.4 to -6.8), and -0.008 ohms (95% CI: -0.02 to 0.001), respectively. Limits of agreement (two standard deviation) between protocols were narrow for whole-body right side, affected arm, unaffected arm, and interarm ratio without any systematic or proportional differences for whole-body right side and the interarm ratio (5.8% to -5.6%, 3.7% to -7.4%, 3.5% to -8.2%, and 5.8% to -5.6%, respectively). Conclusion: The equipotential and sternal notch protocols could be used interchangeably in BCRL assessment. The Clinical Trial Registration number: CTRI/2017/12/010762.
Doubly labelled water (DLW) is considered the criterion method for assessment of total energy exp... more Doubly labelled water (DLW) is considered the criterion method for assessment of total energy expenditure (TEE) and physical activity energy expenditure (PAEE) under free-living conditions; however, it is costly and requires significant technical expertise. Body-worn physical activity monitors are a good proxy for estimating TEE and PAEE, but their accuracy compared to DLW remains uncertain in older women. PURPOSE: This study sought to i) validate three physical activity (PA) monitors for TEE assessment in free-living older women using DLW as the criterion method and ii) determine the accuracy of the PAEE estimates obtained by these monitors. METHODS: Thirty three women (age 60.7 ± 7.1 y; mean BMI 26.9 ± 5.0 kg•m) were recruited for this study. TEE and PAEE were measured over a 14-day period using a standardised protocol for DLW (H2O and H2 O). Women also wore SenseWear armband (SAB), ActiHeartTM (AH) and ActiGraph GT3X (AG) PA monitors continuously, and at the same time, during their waking hours over 7 d, except for water-based activities such as bathing or swimming. RESULTS: Paired t-tests revealed mean differences of -163 ± 307 kcal•d between TEEDLW and TEESAB; -134 ± 279 kcal•d -1 between TEEDLW and TEEAH; and -143 ± 242 kcal•d -1 between TEEDLW and TEEAG (all p<0.05). Measurements from PA monitors underestimated TEE derived from the criterion DLW by 6%-7%. The agreement between the criterion and PA devices for TEE demonstrated concordance (ρc) from 0.51 to 0.75. TEEDLW was strongly correlated with TEEAG (r=0.80; p<0.05). PAEE derived from PA monitors significantly underestimated the criterion PAEE by 18%-68%, with mean differences of -332 ± 333 kcal•d between PAEEDLW and PAEESAB, -124 ± 250 kcal•d -1 between PAEEDLW and PAEEAH and -130 ± 217 kcal•d -1 between PAEEDLW and PAEEAG (all p<0.05). There was a moderate correlation between PAEEDLW and PAEEAG (r=0.61; p<0.05), but ρc was non-existent to moderate, ranging from 0.00 to 0.53. CONCLUSION: There were good levels of agreement between body-worn physical activity monitors and a criterion measurement of TEE in older women under free-living conditions. Physical activity monitors consistently underestimated daily levels of energy expenditure, although agreement with a criterion method was better for estimating TEE, than for PAEE. More work is needed to improve the ability of these PA monitors to accurately measure energy expenditure during daily physical activities.
Proceedings of the 2nd International Conference on Bioelectromagnetism (Cat. No.98TH8269), 1998
A novel method utilising both tetrapolar and bipolar impedance analysis was developed for the mea... more A novel method utilising both tetrapolar and bipolar impedance analysis was developed for the measurement of the impedance of skin and underlying subcutaneous tissue. Impedance and skin-fold thickness were measured at four sites (biceps, triceps, subscapular and suprailiac) conventionally used for measurement of skin-folds and estimation of total body fat. Impedance was highly and significantly correlated (r=0.80 to 0.94) with
Chronic treatment of male Wistar rats with ethanol (15% v/v) in drinking fluid for a period of 3 ... more Chronic treatment of male Wistar rats with ethanol (15% v/v) in drinking fluid for a period of 3 months affected the binding of the chloride channel antagonist, [(35)S]TBPS, to well-washed synaptic membranes and slide-mounted brain slices, the affinity for [(35)S]TBPS in brains of ethanol-treated animals was significantly decreased in comparison to controls while receptor density was increased (P &lt; 0.001). However, other well described treatments, viz. an ethanol-containing liquid diet and chronic inhalation of ethanol failed to demonstrate changes in the binding of [(35)S]TBPS in brain preparations. Our findings suggest that long-term administration of ethanol can induce alterations in the characteristics of the ionophore component of the GABA-benzodiazepine receptor complex. This may have relevance to ethanol-induced neuronal damage.
ABSTRACT Lymphoedema is a chronic debilitating condition that may occur in approximately 25% of w... more ABSTRACT Lymphoedema is a chronic debilitating condition that may occur in approximately 25% of women treated for breast cancer. As the condition progresses, accumulated lymph fluid becomes fibrotic with infiltration of adipose tissue. Bioelectrical impedance spectroscopy is the preferred method for early detection of lymphoedema based on the measurement of impedance of extracellular fluid. The present study assessed whether these impedance measurements could also be used to estimate the adipose tissue content of the arm based on a model previously used to predict whole body composition. Estimates of arm adipose tissue in a cohort of women with lymphoedema were found to be highly correlated (r &gt; 0.82) with measurements of adipose tissue obtained using the reference method of dual energy X-ray absorptiometry. Paired t-tests confirmed that there was no significant difference between the adipose tissue volumes obtained by the two methods. These results support the view that the method shows promise for the estimation of arm adiposity in lymphoedema.
SummaryBioelectrical impedance analysis (BIA) is a practical method to estimate percentage body f... more SummaryBioelectrical impedance analysis (BIA) is a practical method to estimate percentage body fat (%BF). In this systematic review, we aimed to assess validity, responsiveness, reliability and measurement error of BIA methods in estimating %BF in children and adolescents.We searched for relevant studies in Pubmed, Embase and Cochrane through November 2012. Two reviewers independently screened titles and abstracts for inclusion, extracted data and rated methodological quality of the included studies. We performed a best evidence synthesis to synthesize the results, thereby excluding studies of poor quality. We included 50 published studies. Mean differences between BIA and reference methods (gold standard [criterion validity] and convergent measures of body composition [convergent validity]) were considerable and ranged from negative to positive values, resulting in conflicting evidence for criterion validity. We found strong evidence for a good reliability, i.e. (intra‐class) corr...
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