Cardiovascular complications have emerged as a major concern for cancer patients. Many chemotherapy agents are cardiotoxic and some appear to also alter lipid profiles, although the mechanism for this is unknown. We studied plasma lipid levels in 12 breast cancer patients throughout their chemotherapy. Patients received either four cycles of doxorubicin and cyclophosphamide followed by weekly paclitaxel or three cycles of epirubicin, cyclophosphamide and 5’-fluorouracil followed by three cycles of docetaxel. Patients demonstrated a significant reduction (0.32 mmol/L) in high density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (apoA1) levels (0.18 g/L) and an elevation in apolipoprotein B (apoB) levels (0.15 g/L) after treatment. Investigation of the individual chemotherapy agents for their effect on genes involved in lipoprotein metabolism in liver cells showed that doxorubicin decreased ATP binding cassette transporter A1 (ABCA1) via a downregulation of the peroxisomal proliferator activated receptor γ (PPARγ) and liver X receptor α (LXRα) transcription factors. In contrast, ABCA1 levels were not affected by cyclophosphamide or paclitaxel. Likewise, apoA1 levels were reduced by doxorubicin and remained unaffected by cyclophosphamide and paclitaxel. Doxorubicin and paclitaxel both increased apoB protein levels and paclitaxel also decreased low density lipoprotein receptor (LDLR) protein levels. These findings correlate with the observed reduction in HDL-C and apoA1 and increase in apoB levels seen in these patients. The unfavourable lipid profiles produced by some chemotherapy agents may be detrimental in the longer term to cancer patients, especially those already at risk of cardiovascular disease (CVD). This knowledge may be useful in tailoring effective follow-up care plans for cancer survivors.
Persons with spinal cord injury lose lean tissue mass and bone but gain body fat. There is a need to quantify the magnitude of these changes in body composition because there are associated skeletal and cardiovascular health risks. We have compared total body and regional (lower limb) di erences in body composition in a group of males with paraplegia and in healthy able-bodied males matched for age, and height using dual energy X-ray absorptiometry. Although patients and controls had similar body mass indices, signi®cant reductions in lean tissue mass (16% less) and bone (12% less) were observed in those with spinal cord injury. Group di erences were even more pronounced in the lower limb. DEXA also revealed large increases in fat mass in subjects who did not look obese, total fat mass being 47% higher in the paraplegic group. We suggest that DEXA provides a simple and practical means to quantify both whole body and regional changes in body composition associated with spinal cord injury.
Background:Walking is usually undertaken at a speed that coincides with the lowest metabolic cost. Aging however, alters the speed–cost relationship, as preferred walking speeds decrease and energy costs increase. It is unclear to what extent this relationship is affected when older women undertake walking as an exercise modality. The aim of this study was to compare the energetic cost of walking at a self-selected exercise pace for 30 min in older and younger women.Methods:The energetic cost of walking was assessed using the energy equivalent of oxygen consumption measured in 18 young (25 to 49 y) and 20 older (50 to 79 y) women who were asked to walk at their “normal” exercise pace on a motorized treadmill for 30 min.Results:The mass-specific net cost of walking (Cw) was 15% higher and self-selected walking speed was 23% lower in the older women than in the younger group. When speed was held constant, the Cw was 0.30 (J · .kg−1 · m−1) higher in the older women.Conclusions:Preferred exercise pace incurs a higher metabolic cost in older women and needs be taken into consideration when recommending walking as an exercise modality.
Background Self-management is recommended for patients with chronic conditions, but its use with cancer survivors is underexplored. Optimal strategies for achieving lifestyle changes in cancer survivors are not known.
Study design: Cross-sectional study comparing a group of active spinal cord injured (SCI) males carefully matched for age, height, and weight with active able-bodied male controls. Objectives: To compare bone mass of the total body, upper and lower limbs, hip, and spine regions in active SCI and able-bodied individuals. Setting: Outpatient study undertaken in two centres in New Zealand. Methods: Dual energy X-ray absorptiometry (DEXA) scanning was used to determine bone mass. Questionnaires were used to ascertain total time spent in weekly physical activity for each individual. The criterion for entry into the study was regular participation in physical activity of more than 60 min per week, over and above that required for rehabilitation. Results: Seventeen SCI and their able-bodied controls met our required activity criterion. Bone mineral density (BMD) values of the total body and hip regions were signi®cantly lower in the SCI group than in their controls (P=0.0001). Leg BMD and bone mineral content (BMC) were also signi®cantly lower in the SCI group (P=0.0001). By contrast, lumbar spine BMD and arm BMD and BMC did not di er between the SCI and control groups. Arm BMD and BMC were greater (not signi®cant) than the reference norms (LUNAR database) for both groups.
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