Hedley G. Peach

Value of plasma calcium, phosphate, and alkaline phosphatase measurements in the diagnosis of histological osteomalacia

Plasma calcium and phosphate concentrations and alkaline phosphatase activities were examined retrospectively in 50 patients with histologically proven osteomalacia and 50 age- and sex-matched control subjects with normal bone histology. An abnormal plasma alkaline phosphatase activity was more useful than an abnormal plasma calcium or phosphate concentration in distinguishing between normal and osteomalacic subjects, producing a false-negative rate of 14% and a false-positive rate of 8%. False-negative and false-positive rates of 10% and 8% respectively were obtained when the presence of an abnormality in any one of the three biochemical measurements was used as a predictor of histological osteomalacia. When discriminant analysis was applied to plasma calcium, phosphate and alkaline phosphatase together a false-negative rate of 12% and a false-positive rate of 0% was obtained. Sixty-two patients in whom a diagnosis of osteomalacia was suspected were investigated prospectively, using both single biochemical abnormalities and the classification functions derived from the discriminant analysis of all three biochemical measurements to predict the presence or absence of histological osteomalacia. Plasma alkaline phosphatase activity gave false-negative and false-positive rates of 10% and 32% respectively but was a more reliable predictor of abnormal bone histology than were plasma calcium or plasma phosphate concentrations or the presence of an abnormality in any one of the three measurements. Discriminant analysis using plasma calcium, phosphate and alkaline phosphatase together produced a false-negative rate of 16% and a false-positive rate of 10%. We conclude that plasma alkaline phosphatase activity is the best single routine biochemical screening test for osteomalacia, although a high false-positive rate may occur. Direct discriminant analysis of plasma calcium, phosphate and alkaline phosphatase together provides a more sensitive method of detecting histological osteomalacia which should be useful in determining the prevalence of osteomalacia within high-risk populations.

Helicobacter pylori infection and fasting plasma glucose concentration

Background—Helicobacter pylori infection raises basal and meal stimulated serum gastrin concentrations and lowers iron stores, which may in turn reduce fasting plasma glucose concentrations in the population. Aim—To determine whether H pylori infection leads to lower fasting plasma glucose concentrations in the population. Methods—One hundred and seventy three women and 165 men, randomly selected from the electoral rolls of an Australian city, participated in a cardiovascular risk factor survey. Plasma glucose concentrations and H pylori IgG antibody titres were measured. Non-fasting subjects and pregnant women were excluded, as were known diabetics, whose plasma glucose concentrations would be affected by diet and/or medications. Fasting plasma glucose concentrations were logarithmically transformed and the relation with H pylori infection, adjusting for age and other confounding factors, was determined for men and women separately by analyses of variance. Results—Helicobacter pylori infection was significantly associated with fasting plasma glucose concentration among women. Infected women had a lower mean fasting plasma glucose concentration (5.2 mmol/litre; range, 3.9–8.2) than did non-infected women (5.4 mmol/litre; range, 3.9–11.1). Conclusions—Helicobacter pylori infection may lead to lower fasting plasma glucose concentrations among women and should be considered when interpreting concentrations bordering on diabetes.

Health and Safety Problems and Lack of Information among International Visitors Backpacking Through North Queensland

BACKGROUND International visitors to tropical Australia may be exposed to health and safety problems. Because they are younger, stay longer and participate in more activities, backpackers have a greater exposure to such problems than other visitors. METHOD The studys aim was to determine how many backpackers experience problems and lack health and safety information. Four hundred and thirty-one international visitors staying in a random sample of youth hostels and backpacker accommodation in Townsville were surveyed over the summer. RESULTS Sixty two percent experienced a health and safety problem, commonly, insect bites, sunburn, headaches, lacerations, coral cuts, ear infections and diarrhea. Seventeen percent resolved only with professional help. Only 54% of backpackers had been offered health and safety information prior to departure, mainly vaccination advice. CONCLUSION The proportion of backpackers offered health and safety information about tropical Australia, and the breadth of that information, needs to be increased.

Helicobacter pylori antibody titres in serum, plasma and successively thawed specimens: implications for epidemiological and clinical studies.

Agreement between Helicobacter pylori IgG antibodies measured using the Pylori-set EIA-G kit in serum, plasma and successively thawed specimens was studied and the implications for epidemiological and clinical studies assessed. Plasma titres may differ from serum titres by -6% to +8% and therefore may be substituted for serum. The change in titre around the cut off value was -0.31 (se = 5.7, p = 0.96) per thaw. The estimated maximum drop after three thawings, 34.5, would result in only a small decrease in sensitivity (1.3%). For qualitative epidemiological studies, this additional misclassification rate is relatively small. However, positive titres did reduce over successive thawings, with the estimated maximum drop being 11.4% per thaw. Therefore, thawing does need to be considered as a contributing factor when interpreting titre drops in eradication trials. Baseline and follow up specimens from clinical studies should be thawed once only and tested concurrently.

Determinants of basal plasma gastrin levels in the general population

Background: There is considerable variation in basal plasma gastrin levels in healthy subjects. Although high plasma gastrin levels may be causally associated with duodenal ulcer and colorectal cancer, there has been little research to identify the factors that determine basal gastrin levels in the general population.

Australians travelling abroad without health and safety information: how many and who are they?

More than two and a half million Australians travel overseas on short‐term visits every year. Despite the information available on prevention of health problems, there is little data on how many and which Australians travel abroad without health and safety information. The aim of the study was to determine how many and which Australians depart international airports without having received or sought health and safety information. One hundred and forty two travellers were interviewed over three consecutive summer months at two airports in north Queensland. Odds ratios (ORs) and 95% confidence intervals (CIs) for variables which might identify those travellers without information were produced by logistic regression analyses. Fifty one per cent had not been given, and 39% had not sought, any information prior to departure. Information of a medical nature was the type most frequently given to travellers or sought by them. Few or no travellers received, or sought, information about problems related to food an...

Hospital separation rates from osteoporotic and non-osteoporotic fractures in metropolitan and rural Australia

Rural populations of the United Kingdom and Scandinavia have lower hospital discharge and incidence rates for hip fractures than urban ones. We compared hospital separations from fractures in rural health regions of Victoria, Australia, with those in metropolitan regions. Fractures were grouped into those commonly (1A), often (1B) or not often (2) associated with osteoporosis. For group 1A fractures, we found rural separation rates were significantly higher among both men and women who were aged either 20-24 or 45-64. The rural separation rates for group 1B fractures were also significantly higher in these age groups but only among men. For group 2 fractures, rural separation rates were significantly higher among young adults. Fractures of the neck, trunk, radius and ulna, but not neck of the femur, contributed to the rural excess of group 1A fractures. If rural adults are not hospitalised more often, risk factors for group 1 and group 2 fractures, which in the middle aged includes osteoporosis, may be more prevalent in rural Victoria. Our findings suggest that international studies of rural-urban differences in fracture rates are needed which include a range of anatomical sites.

Post-test probability that men in the community with raised plasma ferritin concentrations are hazardous drinkers.

BACKGROUND: Raised plasma ferritin concentrations occur unexpectedly during iron studies done by primary care physicians. Plasma ferritin concentration has been positively associated with alcohol use among men. AIM: To determine the post-test probability that men in the community with raised plasma ferritin concentrations are hazardous drinkers. METHODS: The subjects were 152 men, randomly selected from a citys electoral roll. Nineteen (12.5 (2.7)%, mean (SEM)) admitted to drinking hazardously. The pretest probability of a man being a hazardous drinker was 0.125. This was converted to pretest odds of 0.14. The likelihood ratio (the ratio of the probability of obtaining a raised plasma ferritin concentration in a hazardous drinker (sensitivity) to the probability of obtaining a raised plasma ferritin concentration in a non-hazardous drinker (1-specificity)) was calculated for different plasma ferritin cut off points. RESULTS: A plasma ferritin level of > 652 micrograms/l gave the largest likelihood ratio, 4.16. Post-test odds were obtained by multiplying the pretest odds (0.14) by the likelihood ratio (4.16). A plasma ferritin level of > 652 micrograms/l had a post-test odds for a man being a hazardous drinker of 0.58. This was converted to a post-test probability of 0.37. CONCLUSIONS: Inquiries could usefully be made into the alcohol consumption of men with a plasma ferritin concentration > 652 micrograms/l, as approximately one in three would admit to drinking hazardously.