Cortisol Secretion and Rate of Bone Loss in a Population-Based Cohort of Elderly Men and Women

Although excessive glucocorticoids are a well-recognized cause of osteoporosis, little is known about the role of endogenous glucocorticoids in determining skeletal mass. We have performed a detailed study of the hypothalamic–pituitary–adrenal (HPA) axis to explore the relationships between cortisol secretion and adult bone mass in 151 healthy men and 96 healthy women aged 61 to 73 years. At baseline and 4-year follow-up, bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) at the lumbar spine and proximal femur; a lifestyle questionnaire was completed; and height, weight, and waist and hip circumferences were measured. At follow-up subjects underwent a very low-dose (0.25 mg) dexamethasone suppression test, a low-dose (1 μg) short synacthen test, and a 24-hour urine collection for measurement of cortisol and its metabolites. In men, elevated peak plasma cortisol was associated with accelerated loss of mineral density in the lumbar spine (r = 0.16, P = 0.05). This relationship remained significant after adjustment for testosterone, estradiol, 25-hydroxyvitamin D, and parathyroid hormone levels (r = 0.22, P = 0.01) and after additional adjustment for age, (BM), activity, cigarette and alcohol consumption, and Kellgren/Lawrence score (r = 0.19, P = 0.03). In contrast in women, elevated peak plasma cortisol was associated with lower baseline BMD at the femoral neck (r = −0.23, P = 0.03) and greater femoral neck loss rate (r = 0.24, P = 0.02). There was no association between plasma cortisol concentrations after dexamethasone or urinary total cortisol metabolite excretion and bone density or bone loss rate at any site. These data provide evidence that circulating endogenous glucocorticoids influence the rate of involutional bone loss in healthy individuals.     

The nutritional response to home enteral nutrition in childhood

The nutritional response to home enteral nutrition (HEN) was evaluated in a prospective study of 44 consecutive children (median age 48 months) who received HEN for more than 1 month (median duration 6 months). Three groups were studied: 17 children were stunted, 14 were wasted and 13 were adequately nourished but unlikely to maintain oral intake during anticipated nutritional stress. In the stunted group (median duration of HEN 15 months) there was a significant correlation between improvements in height–for–age z scores and duration of feeds ( r = 0.63; p = 0.006). In the wasted group (median duration of HEN 4 months) all anthropometric indices improved significantly ( p < 0.05). HEN was also successful in maintaining nutritional status in the third group. Thus, supplementary HEN is an effective method of nutritional support for a variety of indications, provided concurrent advice from a nutritional care team is available.     

Diagnosis and clinical associations of zinc depletion following bone marrow transplantation

Following the emergence of biochemical zinc deficiency after bone marrow transplantation, the clinical value of plasma alkaline phosphatase activity as an early indicator of biochemical zinc depletion was investigated in this group of patients. Serial measurements of plasma zinc and alkaline phosphatase activities in 28 consecutive children (median age 8.7 years; 16 males) undergoing bone marrow transplantation were carried out and clinical associations recorded. A significant fall in plasma zinc occurred after the bone marrow transplant, and 19 children developed biochemical zinc deficiency (Zn < 11 mumol/l) at a median of 7 days following the transplant. Zinc depletion was more common in younger patients and in children with diarrhoea. A positive correlation was found between plasma zinc and alkaline phosphatase activities. Zinc depleted patients had more febrile episodes of longer duration and were more likely to have a positive blood culture. Haemopoetic recovery was not affected by zinc deficiency. Following zinc supplementation, alkaline phosphatase showed a significant increase. The sensitivity of a low alkaline phosphatase as a screening test for biochemical zinc deficiency was 83%, with a specificity of 86%. Low alkaline phosphatase activity following bone marrow transplant is an indication for zinc supplements.     

OCCUPATIONAL ASTHMA IN A CHEESE PACKER

Occupational asthma is an increasingly common clinical problem.¹ A worker who develops asthma for the first time when starting work in a new environment may be straightforward to diagnose. However, when asthma occurs after a latent period following initial exposure, or when a pre-existing asthmatic develops work-related symptoms, the occupational link may be less easy to appreciate. This case report concerns a cheese factory worker with pre-existing asthma who experienced severe symptoms when a new process was introduced for drying grated cheese and was able to return to work only after the process was modified. The drying agent responsible has not been previously reported as a cause of asthma.     

FIRST-LINE TREATMENT IN ACUTE NON-DYSENTERIC DIARRHOEA: CLINICAL COMPARISON OF LOPERAMIDE OXIDE,LOPERAMIDE AND PLACEBO

SUMMARY The use of antimicrobial agents for the treatment of acute diarrhoea has become more common with the introduction of quinolone compounds, which are active against most types of bacterial pathogens. Despite the fact that such drugs have been used for empirical therapy or even for prophylaxis, current opinion would restrict their use to specific groups of patients who are likely to show particular benefit from them. Non-specific therapy seems a more appropriate initial treatment for cases of acute, non-dysenteric diarrhoea. Clinical trial data are presented here comparing the effects of loperamide oxide 1 and 2 mg to those of placebo and loperamide 2 mg in this condition. All the drug preparations were significantly superior to placebo, in particular reducing the time to complete relief of symptoms to about 24 hours, as opposed to 45 hours on placebo treatment. Of these preparations, loperamide oxide 1 mg is to be preferred, as it produces fewer constipation-like episodes after treatment. The introduction of loperamide oxide 1 mg represents a useful advance in the non-specific treatment of acute, non-dysenteric diarrhoea.     

On the mechanism of the effects of potassium restriction on blood pressure and renal sodium retention

Dietary potassium restriction increases sodium and chloride retention, whereas potassium administration promotes both diuresis and natriuresis. In epidemiologic and clinical studies, potassium intake is inversely related to blood pressure and is lower in blacks than in whites. The present studies examined the mechanism by which potassium restriction fosters sodium conservation and the impact of race on this response. Twenty-one healthy black and white men and women ingested an isocaloric, potassium-restricted diet (20 mmol/d) containing 180 mmol/d of sodium with and without a potassium supplement (80 mmol/d) for 9 days on two occasions. Additionally, eight of these subjects ingested the same diets for 3 days followed by a water load to determine free water clearance before and during the early phase of dietary potassium restriction. During potassium restriction, mean arterial pressure (MAP) derived from 24-hour blood pressure measurements was higher (85.7 +/- 1.6 mm Hg v 82.0 +/- 1.3 mm Hg; P < 0.001), cumulative sodium excretion lower (984 +/- 59 mmol/d v 1,256 +/- 58 mmol/d; P < 0.001), and weight greater (71.1 +/- 2.1 kg v 69.3 +/- 2.2 kg; P < 0.001). Blacks displayed no greater increase in MAP, although they excreted less sodium overall and less potassium on the potassium-supplemented diet. After a water load, minimum urine osmolality (Uosm) was lower (53.0 +/- 3.0 mOsm/L v 65.6 +/- 3.5 mOsm/L; P = 0.01) and free water clearance greater (4.44 +/- 0.59 mL/min v3.72 +/- 0.58 mL/min; P = 0.009) during potassium restriction. In conclusion, in healthy, normotensive subjects, potassium restriction was associated with an increase in blood pressure and volume expansion effected by increased renal sodium and chloride retention. Potassium restriction was also associated with increased free water clearance and enhanced diluting capacity consistent with augmentation of Na+, K+:2Cl- cotransporter activity in the thick ascending limb of Henle. This mechanism may play an important role in the renal adaptation required for potassium conservation, but at the expense of sodium chloride retention and an elevation in blood pressure.     

Bacterial contamination of enteral feeds

Enteral nutrition is increasingly used to provide nutritional support for children in hospital and at home. No suitable formula is available for preschool children, however, and until recently a modular feed has been prepared. The hypotheses were examined that the use of a modular feed is associated with increased bacterial contamination, and that contamination is more common in the home than in hospital. Thirty five children receiving enteral nutrition initially in hospital and subsequently at home were allocated randomly to receive either a modular feed or a newly available sterile ready to use paediatric feed. Samples of feed were taken from the nutrient container immediately after filling and at the end of feeding. The results show that feed contamination is common in hospital and at home, but significantly more so at home. The data indicate the importance of hygiene training for parents and the desirability of a ready to use formula.     

Acetylsalicylic Acid vs. Metoprolol in Migraine Prophylaxis - A Double-Blind Cross-Over Study

In a double blind cross-over study, 28 patients, 5 male and 23 female, aged 31 +/- 14 years, after a run-in period of 8 weeks, were treated for 3 months with acetylsalicylic acid and for another 3 months with metoprolol, both in a prophylactic mode. Attack frequency was reduced significantly with both therapeutic regimens (ASA p less than 0.001, metoprolol p less than 0.00005). Reduction of attacks below 50% was seen with metoprolol in 14 cases, and with ASA in three cases. Even though ASA was of statistically significant efficacy in migraine prophylaxis, it clearly is not the drug of first choice in migraine prophylaxis.