Objectives: To determine whether acute exercise associated muscle cramping (EAMC) in distance runners is related to changes in serum electrolyte concentrations and hydration status. Methods: A cohort of 72 runners participating in an ultra-distance road race was followed up for the development of EAMC. All subjects were weighed before and immediately after the race. Blood samples were taken before the race, immediately after the race, and 60 minutes after the race. Blood samples were analysed for glucose, protein, sodium, potassium, calcium, and magnesium concentrations, as well as serum osmolality, haemoglobin, and packed cell volume. Runners who suffered from acute EAMC during the race formed the cramp group (cramp, n = 21), while runners with no history of EAMC during the race formed the control group (control, n = 22). Results: There were no significant differences between the two groups for pre-race or post-race body weight, per cent change in body weight, blood volume, plasma volume, or red cell volume. The immediate post-race serum sodium concentration was significantly lower (p = 0.004) in the cramp group (mean (SD), 139.8 (3.1) mmol/l) than in the control group (142.3 (2.1) mmol/l). The immediate post-race serum magnesium concentration was significantly higher (p = 0.03) in the cramp group (0.73 (0.06) mmol/l) than in the control group (0.67 (0.08) mmol/l). Conclusions: There are no clinically significant alterations in serum electrolyte concentrations and there is no alteration in hydration status in runners with EAMC participating in an ultra-distance race.

Objectives: To describe associations between birthweight and infant, child and early adult mortality from natural causes in a remote Australian Aboriginal community against a background of rapidly changing mortality due to better health services. Design, participants and setting: Cohort study of 995 people with recorded birthweights who were born between 1956 and 1985 to an Aboriginal mother in a remote Australian Aboriginal community. Participants were followed through to the end of 2006. Main outcome measures: Rates of natural deaths of infants (aged 0 to < 1 year), children (aged 1 to < 15 years) and adults (aged 15 to < 37 years), compared by birth intervals (1956–1965, 1966–1975 and 1976–1985 for infants and children, and 1956–1962 and 1963–1969 for adults) and by birthweight. Results: Birthweights were low, but increased over time. Deaths among infants and children decreased dramatically over time, but deaths among adults did not. Lower birthweights were associated with higher mortality. Adjusted for birth interval, hazard ratios for deaths among infants, children and adults born at weights below their group birthweight medians were 2.30 (95% CI, 1.13–4.70), 1.78 (95% CI, 1.03–3.07) and 3.49 (95% CI, 1.50–8.09), respectively. The associations were significant individually for deaths associated with diarrhoea in infants, with cardiovascular and renal disease in adults, and marginally significant for deaths from pulmonary causes in children and adults. Conclusion: The striking improvements in infant and child survival over time must be applauded. We confirmed a predisposing effect of lower birthweights on deaths in infants and children, and showed, for the first time, an association between lower birthweights and deaths in adults. Together, these factors are probably contributing to the current epidemic of chronic disease in Aboriginal people, an effect that will persist for decades. Similar phenomena are probably operating in developing countries.

The objective of this study was to investigate the number of glomerular profiles that are required for accurate estimates of mean profile area in a renal biopsy series. Slides from 384 renal biopsies from one center were reviewed. They contained a median of seven glomerular profiles or of four profiles without sclerosis. Profile areas were measured using stereologic point counting. The "true individual mean" for each biopsy was calculated and the "true population mean" for groups of biopsies derived. Individual and population "random sample means" then were calculated from a random sampling of profiles in each biopsy and were compared with true means for the same biopsies. The effect on the true population means of the entire group of biopsies was also assessed, as the minimum number of glomerular profiles that were required for inclusion was changed. In a single biopsy, random sampling of >10 profiles without exclusions and of eight profiles or more without sclerosis reliably estimated the true mean areas. In a group of 30 biopsies, random sampling of five or more glomeruli per biopsy reliably estimated the true population mean. In the aggregate series, inclusion of all 384 biopsies produced the most robust true population mean; the reliability of the estimates decreased as the numbers of eligible biopsies diminished with increasing requisite minimum numbers of profiles per biopsy. We conclude that, while >10 profiles might be needed for reliable area estimates in a single biopsy, far fewer profiles per biopsy can suffice when groups of biopsies are studied. In analyses of groups of biopsies, all available biopsies should be used without consideration of the number of glomerular profiles in each. Stipulation of a specific minimum number of glomeruli in each biopsy for inclusion reduces the power of analyses because fewer biopsies are available for evaluation.

In late 1995, a treatment program for renal disease and hypertension was introduced into a remote Aboriginal community. Over the next 3.5 years, mean blood pressure levels were markedly reduced, renal function stabilised, and rates of both renal and non‐renal deaths declined significantly. In 1999–2000, responsibility for the program was passed to the community's local Health Board, which subsequently faced deficiencies in clinical information systems and a shortfall in funding. After the handover, the intensity of the program declined, and compliance with medicines fell. Blood pressures in the treatment cohort increased, renal function deteriorated, and rates of deaths from natural causes subsequently rose. From 2002 to mid‐2003, the adjusted risks of renal and non‐renal deaths in the treatment cohort were three and 9.5 times the respective risks of people during the first 18 months of treatment in the systematic phase of the program. Sustained vigorous activity, both in treatment of people already identified and in community screening for treatment eligibility, is required to maintain good results in any chronic disease program. Adequate resources and well supported staff are essential, and constant evaluation is needed to follow outcomes and modify strategies as necessary.

People with multiple myeloma (MM) often experience disease symptoms and treatment toxicities that can be alleviated through physical activity (PA). However, the majority of people with MM are insufficiently active. This study explored PA among people with MM, including differences by treatment stage, symptoms and demographics, and programming preferences. Overall, 126 people with MM (77% response rate) completed the survey. Pre-diagnosis, 25.4% were sufficiently active, with 12.0% remaining active after treatment. Respondents who were physically active pre-diagnosis were 46.7 times (95% confidence intervals CI: 2.03, 1072.1) more likely to meet PA guidelines following an MM diagnosis compared to people not meeting guidelines pre-diagnosis. Experiencing MM symptoms and receiving PA advice from healthcare professionals were not associated with meeting PA guidelines. People with MM were interested in exercise programs (55%) that are low-cost (77%), offered at flexible times (74%), and at locations close to home (69%), both during active treatment and remission (57%), and supervised by an exercise oncology specialist (48%). People with MM, particularly those insufficiently active prior to diagnosis, should be offered convenient, low-cost exercise programs supervised by an exercise oncology specialist to increase PA participation.