Nutritional support in chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND: The efficacy of nutritional support in the management of malnutrition in chronic obstructive pulmonary disease (COPD) is controversial. Previous meta-analyses, based on only cross-sectional analysis at the end of intervention trials, found no evidence of improved outcomes. OBJECTIVE: The objective was to conduct a meta-analysis of randomized controlled trials (RCTs) to clarify the efficacy of nutritional support in improving intake, anthropometric measures, and grip strength in stable COPD. DESIGN: Literature databases were searched to identify RCTs comparing nutritional support with controls in stable COPD. RESULTS: Thirteen RCTs (n = 439) of nutritional support [dietary advice (1 RCT), oral nutritional supplements (ONS; 11 RCTs), and enteral tube feeding (1 RCT)] with a control comparison were identified. An analysis of the changes induced by nutritional support and those obtained only at the end of the intervention showed significantly greater increases in mean total protein and energy intakes with nutritional support of 14.8 g and 236 kcal daily. Meta-analyses also showed greater mean (±SE) improvements in favor of nutritional support for body weight (1.94 ± 0.26 kg, P < 0.001; 11 studies, n = 308) and grip strength (5.3%, P < 0.050; 4 studies, n = 156), which was not shown by ANOVA at the end of the intervention, largely because of bias associated with baseline imbalance between groups. CONCLUSION: This systematic review and meta-analysis showed that nutritional support, mainly in the form of ONS, improves total intake, anthropometric measures, and grip strength in COPD. These results contrast with the results of previous analyses that were based on only cross-sectional measures at the end of intervention trials.

The influence of smoking status on malnutrition risk and 1-year mortality in outpatients with chronic obstructive pulmonary disease.

Introduction:  Smoking status in outpatients with chronic obstructive pulmonary disease (COPD) has been associated with a low body mass index (BMI) and reduced mid-arm muscle circumference (Cochrane & Afolabi, 2004). Individuals with COPD identified as malnourished have also been found to be twice as likely to die within 1 year compared to non-malnourished patients (Collins et al., 2010). Although malnutrition is both preventable and treatable, it is not clear what influence current smoking status, another modifiable risk factor, has on malnutrition risk. The current study aimed to establish the influence of smoking status on malnutrition risk and 1-year mortality in outpatients with COPD. Methods:  A prospective nutritional screening survey was carried out between July 2008 and May 2009 at a large teaching hospital (Southampton General Hospital) and a smaller community hospital within Hampshire (Lymington New Forest Hospital). In total, 424 outpatients with a diagnosis of COPD were routinely screened using the ‘Malnutrition Universal Screening Tool’, ‘MUST’ (Elia, 2003); 222 males, 202 females; mean (SD) age 73 (9.9) years; mean (SD) BMI 25.9 (6.4) kg m−2. Smoking status on the date of screening was obtained for 401 of the outpatients. Severity of COPD was assessed using the GOLD criteria, and social deprivation determined using the Index of Multiple Deprivation (Nobel et al., 2008). Results:  The overall prevalence of malnutrition (medium + high risk) was 22%, with 32% of current smokers at risk (who accounted for 19% of the total COPD population). In comparison, 19% of nonsmokers and ex-smokers were likely to be malnourished [odds ratio, 1.965; 95% confidence interval (CI), 1.133–3.394; P = 0.015]. Smoking status remained an independent risk factor for malnutrition even after adjustment for age, social deprivation and disease-severity (odds ratio, 2.048; 95% CI, 1.085–3.866; P = 0.027) using binary logistic regression. After adjusting for age, disease severity, social deprivation, smoking status, malnutrition remained a significant predictor of 1-year mortality [odds ratio (medium + high risk versus low risk), 2.161; 95% CI, 1.021–4.573; P = 0.044], whereas smoking status did not (odds ratio for smokers versus ex-smokers + nonsmokers was 1.968; 95% CI, 0.788–4.913; P = 0.147). Discussion:  This study highlights the potential importance of combined nutritional support and smoking cessation in order to treat malnutrition. The close association between smoking status and malnutrition risk in COPD suggests that smoking is an important consideration in the nutritional management of malnourished COPD outpatients. Conclusions:  Smoking status in COPD outpatients is a significant independent risk factor for malnutrition and a weaker (nonsignificant) predictor of 1-year mortality. Malnutrition significantly predicted 1 year mortality. References:  Cochrane, W.J. & Afolabi, O.A. (2004) Investigation into the nutritional status, dietary intake and smoking habits of patients with chronic obstructive pulmonary disease. J. Hum. Nutr. Diet.17, 3–11. Collins, P.F., Stratton, R.J., Kurukulaaratchym R., Warwick, H. Cawood, A.L. & Elia, M. (2010) ‘MUST’ predicts 1-year survival in outpatients with chronic obstructive pulmonary disease. Clin. Nutr.5, 17. Elia, M. (Ed) (2003) The ‘MUST’ Report. BAPEN. http://www.bapen.org.uk (accessed on March 30 2011). Nobel, M., McLennan, D., Wilkinson, K., Whitworth, A. & Barnes, H. (2008) The English Indices of Deprivation 2007. http://www.communities.gov.uk (accessed on March 30 2011).

Prevalence and prognostic significance of secondary lymphedema following breast cancer

Background The adverse consequences of lymphedema following breast cancer in relation to physical function and quality of life are clear; however, its potential relationship with survival has not been investigated. Our purpose was to determine the prevalence of lymphedema and associated upper-body symptoms at 6 years following breast cancer and to examine the prognostic significance of lymphedema with respect to overall 6-year survival (OS). Methods and Results A population-based sample of Australian women (n=287) diagnosed with invasive, unilateral breast cancer was followed for a median of 6.6 years and prospectively assessed for lymphedema (using bioimpedance spectroscopy [BIS], sum of arm circumferences [SOAC], and self-reported arm swelling), a range of upper-body symptoms, and vital status. OS was measured from date of diagnosis to date of death or last follow-up. Kaplan-Meier methods were used to calculate OS and Cox proportional hazards models quantified the risk associated with lymphedema. Approximately 45% of women had reported at least one moderate to extreme symptom at 6.6 years postdiagnosis, while 34% had shown clinical evidence of lymphedema, and 48% reported arm swelling at least once since baseline assessment. A total of 27 (9.4%) women died during the follow-up period, and lymphedema, diagnosed by BIS or SOAC between 6–18 months postdiagnosis, predicted mortality (BIS: HR=2.5; 95% CI: 0.9, 6.8, p=0.08; SOAC: 3.0; 95% CI: 1.1, 8.7, p=0.04). There was no association (HR=1.2; 95% CI: 0.5, 2.6, p=0.68) between self-reported arm swelling and OS. Conclusions These findings suggest that lymphedema may influence survival following breast cancer treatment and warrant further investigation in other cancer cohorts and explication of a potential underlying biology.

Risk of metabolic syndrome among children living in metropolitan Kuala Lumpur: A case control study

Background With the increasing prevalence of childhood obesity, the metabolic syndrome has been studied among children in many countries but not in Malaysia. Hence, this study aimed to compare metabolic risk factors between overweight/obese and normal weight children and to determine the influence of gender and ethnicity on the metabolic syndrome among school children aged 9-12 years in Kuala Lumpur and its metropolitan suburbs. Methods A case control study was conducted among 402 children, comprising 193 normal-weight and 209 overweight/obese. Weight, height, waist circumference (WC) and body composition were measured, and WHO (2007) growth reference was used to categorise children into the two weight groups. Blood pressure (BP) was taken, and blood was drawn after an overnight fast to determine fasting blood glucose (FBG) and full lipid profile, including triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC). International Diabetes Federation (2007) criteria for children were used to identify metabolic syndrome. Results Participants comprised 60.9% (n = 245) Malay, 30.9% (n = 124) Chinese and 8.2% (n = 33) Indian. Overweight/obese children showed significantly poorer biochemical profile, higher body fat percentage and anthropometric characteristics compared to the normal-weight group. Among the metabolic risk factors, WC ≥90th percentile was found to have the highest odds (OR = 189.0; 95%CI 70.8, 504.8), followed by HDL-C≤1.03 mmol/L (OR = 5.0; 95%CI 2.4, 11.1) and high BP (OR = 4.2; 95%CI 1.3, 18.7). Metabolic syndrome was found in 5.3% of the overweight/obese children but none of the normal-weight children (p < 0.01). Overweight/obese children had higher odds (OR = 16.3; 95%CI 2.2, 461.1) of developing the metabolic syndrome compared to normal-weight children. Binary logistic regression showed no significant association between age, gender and family history of communicable diseases with the metabolic syndrome. However, for ethnicity, Indians were found to have higher odds (OR = 5.5; 95%CI 1.5, 20.5) compared to Malays, with Chinese children (OR = 0.3; 95%CI 0.0, 2.7) having the lowest odds. Conclusions We conclude that being overweight or obese poses a greater risk of developing the metabolic syndrome among children. Indian ethnicity is at higher risk compared to their counterparts of the same age. Hence, primary intervention strategies are required to prevent this problem from escalating.

Conditioning of the Achilles tendon via ankle exercise improves correlations between sonographic measures of tendon thickness and body anthropometry

Although conditioning is routinely used in mechanical tests of tendon in vitro, previous in vivo research evaluating the influence of body anthropometry on Achilles tendon thickness has not considered its potential effects on tendon structure. This study evaluated the relationship between Achilles tendon thickness and body anthropometry in healthy adults both before and after resistive ankle plantarflexion exercise. A convenience sample of 30 healthy male adults underwent sonographic examination of the Achilles tendon in addition to standard anthropometric measures of stature and body weight. A 10-5 MHz linear array transducer was used to acquire longitudinal sonograms of the Achilles tendon, 20 mm proximal to the tendon insertion. Participants then completed a series (90-100 repetitions) of conditioning exercises against an effective resistance between 100% and 150% body weight. Longitudinal sonograms were repeated immediately on completion of the exercise intervention, and anteroposterior Achilles tendon thickness was determined. Achilles tendon thickness was significantly reduced immediately following conditioning exercise (t = 9.71, P < 0.001), resulting in an average transverse strain of -18.8%. In contrast to preexercise measures, Achilles tendon thickness was significantly correlated with body weight (r = 0.72, P < 0.001) and to a lesser extent height (r = 0.45, P < 0.01) and body mass index (r = 0.63, P < 0.001) after exercise. Conditioning of the Achilles tendon via resistive ankle exercises induces alterations in tendon structure that substantially improve correlations between Achilles tendon thickness and body anthropometry. It is recommended that conditioning exercises, which standardize the load history of tendon, are employed before measurements of sonographic tendon thickness in vivo.

Measuring voluntary dietary change in response to exercise : a focus on dietary fat

Traditional treatments for weight management have focussed on prescribed dietary restriction or regular exercise, or a combination of both. However recidivism for such prescribed treatments remains high, particularly among the overweight and obese. The aim of this thesis was to investigate voluntary dietary changes in the presence of prescribed mixed-mode exercise, conducted over 16 weeks. With the implementation of a single lifestyle change (exercise) it was postulated that the onerous burden of concomitant dietary and exercise compliance would be reduced, leading to voluntary lifestyle changes in such areas as diet. In addition, the failure of exercise as a single weight loss treatment has been reported to be due to compensatory energy intakes, although much of the evidence is from acute exercise studies, necessitating investigation of compensatory intakes during a long-term exercise intervention. Following 16 weeks of moderate intensity exercise, 30 overweight and obese (BMI≥25.00 kg.m-2) men and women showed small but statistically significant decreases in mean dietary fat intakes, without compensatory increases in other macronutrient or total energy intakes. Indeed total energy intakes were significantly lower for men and women following the exercise intervention, due to the decreases in dietary fat intakes. There was a risk that acceptance of the statistical validity of the small changes to dietary fat intakes may have constituted a Type 1 error, with false rejection of the Null hypothesis. Oro-sensory perceptions to changes in fat loads were therefore investigated to determine whether the measured dietary fat changes were detectable by the human palate. The ability to detect small changes in dietary fat provides sensory feedback for self-initiated dietary changes, but lean and overweight participants were unable to distinguish changes to fat loads of similar magnitudes to that measured in the exercise intervention study. Accuracy of the dietary measurement instrument was improved with the effects of random error (day-to-day variability) minimised with the use of a statistically validated 8-day, multiple-pass, 24 hour dietary recall instrument. However systematic error (underreporting) may have masked the magnitude of dietary change, particularly the reduction in dietary fat intakes. A purported biomarker (plasma Apolipoprotein A-IV) (apoA-IV) was subsequently investigated, to monitor systematic error in self-reported dietary intakes. Changes in plasma apoA-IV concentrations were directly correlated with increased and decreased changes to dietary fat intakes, suggesting that this objective marker may be a useful tool to improve the accuracy of dietary measurement in overweight and obese populations, who are susceptible to dietary underreporting.

Re-cementing in revision total hip replacement

Removal of well-fixed cement at revision surgery risks bone loss, cortical perforation and fracture, is time-consuming, technically demanding and carries increased risks for the patient. The cement-in-cement technique avoids these problems and when used appropriately has given favourable results at our centre when used on both the femoral and acetabular sides of the articulation. A modified technique has also been used in selected cases of infection and peri-prosthetic fracture. This chapter highlights the results to date and the operative techniques employed. It is essential to recognise that this technique relies fundamentally on the presence of a well-fixed cement mantle, and it is imperative that the criteria laid out are adhered to in order to achieve success. If there is loosening or lysis on the femoral side extending distal to the lesser trochanter or around more than just the periphery of the acetabular cement mantle, then alternative revision techniques should be employed.

Anatomy of a submarine pyroclastic flow and associated turbidity current : July 2003 dome collapse, Soufrière Hills volcano, Montserrat, West Indies

The 12 to 13 July 2003 andesite lava dome collapse at the Soufrière Hills volcano, Montserrat, provides the first opportunity to document comprehensively both the sub-aerial and submarine sequence of events for an eruption. Numerous pyroclastic flows entered the ocean during the collapse, depositing approximately 90% of the total material into the submarine environment. During peak collapse conditions, as the main flow penetrated the air–ocean interface, phreatic explosions were observed and a surge cloud decoupled from the main flow body to travel 2 to 3 km over the ocean surface before settling. The bulk of the flow was submerged and rapidly mixed with sea water forming a water-saturated mass flow. Efficient sorting and physical differentiation occurred within the flow before initial deposition at 500 m water depth. The coarsest components (∼60% of the total volume) were deposited proximally from a dense granular flow, while the finer components (∼40%) were efficiently elutriated into the overlying part of the flow, which evolved into a far-reaching turbidity current.

How important is length? : mechanical testing and measurement of a cemented, polished, tapered femoral implant

Total hip arthroplasty (THA) has a proven clinical record for providing pain relief and return of function to patients with disabling arthritis. There are many successful options for femoral implant design and fixation. Cemented, polished, tapered femoral implants have been shown to have excellent results in national joint registries and long-term clinical series. These implants are usually 150mm long at their lateral aspect. Due to their length, these implants cannot always be offered to patients due to variations in femoral anatomy. Polished, tapered implants as short as 95mm exist, however their small proximal geometry (neck offset and body size) limit their use to smaller stature patients. There is a group of patients in which a shorter implant with a maintained proximal body size would be advantageous. There are also potential benefits to a shorter implant in standard patient populations such as reduced bone removal due to reduced reaming, favourable loading of the proximal femur, and the ability to revise into good proximal bone stock if required. These factors potentially make a shorter implant an option for all patient populations. The role of implant length in determining the stability of a cemented, polished, tapered femoral implant is not well defined by the literature. Before changes in implant design can be made, a better understanding of the role of each region in determining performance is required. The aim of the thesis was to describe how implant length affects the stability of a cemented, polished, tapered femoral implant. This has been determined through an extensive body of laboratory testing. The major findings are that for a given proximal body size, a reduction in implant length has no effect on the torsional stability of a polished, tapered design, while a small reduction in axial stability should be expected. These findings are important because the literature suggests that torsional stability is the major determinant of long-term clinical performance of a THA system. Furthermore, a polished, tapered design is known to be forgiving of cement-implant interface micromotion due to the favourable wear characteristics. Together these findings suggest that a shorter polished, tapered implant may be well tolerated. The effect of a change in implant length on the geometric characteristics of polished, tapered design were also determined and applied to the mechanical testing. Importantly, interface area does play a role in stability of the system; however it is the distribution of the interface and not the magnitude of the area that defines stability. Taper angle (at least in the range of angles seen in this work) was shown not to be a determinant of axial or torsional stability. A range of implants were tested, comparing variations in length, neck offset and indication (primary versus cement-in-cement revision). At their manufactured length, the 125mm implants were similar to their longer 150mm counterparts suggesting that they may be similarly well tolerated in the clinical environment. However, the slimmer cement-in-cement revision implant was shown to have a poorer mechanical performance, suggesting their use in higher demand patients may be hazardous. An implant length of 125mm has been shown to be quite stable and the results suggest that a further reduction to 100mm may be tolerated. However, further work is required. A shorter implant with maintained proximal body size would be useful for the group of patients who are unable to access the current standard length implants due to variations in femoral anatomy. Extending the findings further, the similar function with potential benefits of a shorter implant make their application to all patients appealing.