Fuelling the athlete with type 1 diabetes.

People with type 1 diabetes (T1DM) want to enjoy the benefits of sport and exercise, but management of diabetes in this context is complex. An understanding of the physiology of exercise in health, and particularly the control of fuel mobilization and metabolism, gives an idea of problems which may arise in managing diabetes for sport and exercise. Athletes with diabetes need to be advised on appropriate diet to maximize performance and reduce fatigue. Exercise in diabetes is complicated both by hypoglycaemia and hyperglycaemia in particular circumstances and explanations are advanced which can provide a theoretical underpinning for possible management strategies. Management strategies are proposed to improve glycaemic control and performance.

Strongyloides stercoralis hyperinfection: difficulties in diagnosis and treatment.

Immunocompromised patients who are infected with Strongyloides stercoralis may develop a potentially fatal auto-infection syndrome characterised by non-specific pulmonary and gastrointestinal symptoms and Gram negative sepsis. We present the case of one such patient who underwent a negative laparotomy for a presumed intra-abdominal surgical catastrophe with a subsequent protracted stay on the intensive care unit. Once the diagnosis of strongyloidiasis was made, the patient was successfully treated with subcutaneous antihelminthic drugs. With appropriate screening for and eradication of strongyloides in those with immune compromise, or in those about to start immunosuppressive therapy, potentially fatal episodes of hyperinfection could be avoided. In the absence of screening, severe strongyloidiasis should be suspected in immunosuppressed individuals who have travelled to or resided in an endemic area and present with the characteristic features. Awareness of the signs of hyperinfection amongst those involved in acute care could prevent unnecessary morbidity and mortality in these patients.

Survey of glargine use in 115 pregnant women with Type 1 diabetes.

AIM: To examine pregnancy outcome in women with Type 1 diabetes treated with glargine. METHODS: Glargine use in pregnancy was surveyed over 2 years in 20 UK obstetric-diabetes centres. Outcomes, including maternal complications, miscarriage, congenital abnormalities, perinatal morbidity and mortality, were recorded in a standardized format. RESULTS: Outcomes on 109 babies from 115 women with Type 1 diabetes were collected. Insulin glargine was used prior to pregnancy in 69% of women, started during pregnancy in 30%, and stopped at booking in one patient. Insulin aspart was the bolus insulin in 45%, lispro in 42% and human soluble in 8% of women. HbA(1c) fell from 8.1 +/- 0.2% at booking to 6.8 +/- 0.1% during the third trimester. Background retinopathy developed in one patient, worsened in seven and laser photocoagulation was required in three women. Preeclampsia occurred in 12%, and 14% of women had more than one episode of severe hypoglycaemia. One hundred and nine babies were live born, with six miscarriages and no neonatal deaths. The mean gestational age was 37.5 weeks, and mean birth weight was 3500 g. Three babies had congenital abnormalities (malformation rate = 28/1000). Neonatal hypoglycaemia was seen in 46% and hyperbilirubinaemia in 22% of babies. No major adverse outcome was noted in a smaller subset of five Type 2 and seven gestational diabetes patients on glargine. CONCLUSIONS: The use of glargine in Type 1 diabetes during pregnancy was not associated with any unexpected adverse maternal or fetal outcome in this study.

Pregnancy outcome in Type 1 diabetes mellitus treated with insulin lispro (Humalog).

AIMS: The use of insulin lispro in pregnancy has not been systematically investigated despite its increasing use. Pooled data from seven centres with experience in the use of insulin lispro were accumulated to evaluate pregnancy outcome in women with Type 1 diabetes. METHODS: Seven units with specialist obstetric diabetes services were recruited to describe their total experience with insulin lispro in pregnancy. Outcomes with respect to the rate of miscarriage, congenital abnormality, perinatal mortality and maternal parameters were recorded in a standardized format. RESULTS: Outcomes on 71 babies from 76 pregnancies were documented. There were six (7.8%) early miscarriages. All 71 babies were liveborn with a mean gestational age of 37.2 weeks, and median birthweight of 3230 g. Seven babies weighed > 4 kg. There were four congenital abnormalities (5.6%). There was a 72% increase in the mean insulin dose (0.75-1.29 IU/kg per day). Maternal glycaemic control improved throughout pregnancy. No women developed retinopathy de novo during pregnancy and six with established retinopathy required laser therapy during pregnancy. CONCLUSIONS: The use of insulin lispro in Type 1 diabetes during pregnancy results in outcomes comparable to other large studies of diabetic pregnancy.

Possible functional regression of insulinoma with prolonged octreotide.

A 75 year old woman was treated for over three years with the somatostatin analogue, octreotide for an insulinoma. She had presented in a hypoglycaemic coma. C-peptide and insulin concentrations were both raised and an area of increased vascularity within the pancreas was shown by angiography. No lesion was found at laparotomy and no resection was performed. After over three years of octreotide treatment it was withdrawn for a week. Her insulin and C-peptide concentrations were greatly reduced at this time and remained so.

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.

Cardiovascular and metabolic responses to adrenaline infusion in patients with short-term hypothyroidism.

OBJECTIVE: The relation between the clinical manifestations of thyroid disease (both hypo and hyper-thyroidism) and tissue sensitivity to catecholamines remains uncertain. It has been suggested that tissue adrenergic responsiveness is decreased in hypothyroidism, but the reports have been conflicting and have invariably focused on a single physiological response. Therefore the aim of the present study was to determine in patients with moderate, short-term, symptomatic hypothyroidism the responses of heart rate, systolic and diastolic blood pressure, forearm blood flow and metabolic rate to adrenaline infused at a rate known to achieve plasma concentrations in the middle of the physiological range. PATIENTS: Ten subjects (5M, age 43 +/- 3 years, mean +/- SEM) were studied. All were on thyroxine replacement for hypothyroidism following either thyroidectomy or radioactive iodine and had been biochemically euthyroid for at least 6 months. DESIGN: Studies were performed in random order. One study was undertaken on full replacement therapy and the other after 50 micrograms thyroxine daily for 2 weeks. After basal, supine measurements adrenaline was infused at 25 ng/kg/min for 30 minutes. MEASUREMENTS: Heart rate, blood pressure, blood glucose, metabolic rate and forearm blood flow were measured at rest and at 10-minute intervals throughout the adrenaline infusion. RESULTS: Free T4 (10.6 +/- 1.3 vs 17.6 +/- 2.0 pmol/l, P < 0.001) and free T3 (3.6 +/- 0.2 vs 4.6 +/- 0.3 pmol/l, P < 0.01) concentrations were significantly lower on 50 micrograms thyroxine than full replacement therapy. Fasting blood glucose concentrations (4.7 +/- 0.2 vs 4.7 +/- 0.1 mmol/l) were similar. The resting adrenaline concentrations were comparable, 0.29 +/- 0.18 and 0.24 +/- 0.14 nmol/l on 50 micrograms thyroxine and full replacement therapy respectively, and increased to a similar level (2.36 +/- 0.39 and 2.36 +/- 0.35 nmol/l) throughout the adrenaline infusion. The resting heart rate and metabolic rate were significantly lower on 50 micrograms thyroxine than full replacement therapy (68 +/- 2 vs 72 +/- 3 beats/min, P < 0.01; and 4.48 +/- 0.35 vs 4.88 +/- 0.39 kJ/min, P < 0.01) respectively, but the increase in heart rate (7 +/- 2 vs 8 +/- 2 beats/min) and metabolic rate (0.43 +/- 0.09 vs 0.43 +/- 0.06 kJ/min) did not differ on the two study days. Resting systolic blood pressure, diastolic blood pressure and forearm blood flow were comparable on 50 micrograms thyroxine and full replacement therapy as were the changes in systolic blood pressure (1 +/- 1 vs 1 +/- 1 mmHg), diastolic blood pressure (-7 +/- 2 vs -7 +/- 1 mmHg), forearm blood flow (1.4 +/- 0.1 vs 1.7 +/- 0.2 ml/min/100ml forearm) and blood glucose concentration (0.7 +/- 0.1 vs 0.7 +/- 0.1 mmol/l). CONCLUSIONS: Patients with short-term hypothyroidism appear to have a normal response to adrenaline infusion despite reduced baseline heart rate and metabolic rate. Thus, under physiological and mild pathophysiological conditions there appears to be no evidence of any synergy between thyroid status and sensitivity to catecholamines.

The use of capsaicin cream in a case of erythromelalgia.

We present a case of erythromelalgia in a 68 year old lady who responded, within 48 hours, to a twice daily topical application of capsaicin cream 0.025%. Capsaicin cream was stopped after 2 months, and 6 months later the patient continued to have the symptomatic relief she experienced initially.

Twenty-four hour ambulatory blood pressure and heart rate in a patient with a predominantly adrenaline secreting phaeochromocytoma.

In this report, we present the symptoms, biochemical investigations, 24 hour ambulatory blood pressure and heart rate recordings in a patient before and following removal of a predominantly adrenaline-secreting phaeochromocytoma. The symptoms were of episodic shaking, faintness, nausea, palpitations, sweating and panic, chest and neck pain with headache, and are consistent with previous reports. Ambulatory blood pressure recording demonstrated that mean daily blood pressure was normal, with normal diurnal variation, and two episodes of severe hypertension and bradycardia coincident with symptoms (MAP 150 mmHg and HR 49 beats/minute, MAP 178 mmHg and HR 29 beats/minute, respectively), not reported in predominantly adrenaline-secreting phaeochromocytoma.

Metabolic heat production and cardiovascular responses to an incremental intravenous infusion of adrenaline in healthy subjects.

Increased circulating adrenaline causes a rise in metabolic heat production and well characterized cardiovascular changes. To further characterize these responses we measured metabolic heat production and cardiovascular responses during an incremental infusion of adrenaline (A) in ten healthy subjects (five male; aged 21 to 27 years) and in a placebo controlled (C) study. Plasma adrenaline was unchanged during C, but increased during A (baseline 0.2 nmol/l and low, intermediate and high dose 1.0, 1.9 and 3.1 nmol/l respectively). There was a stepwise increase in metabolic heat production during A (from baseline +0.19, +0.51 and +0.77 kJ/min) with a fall during C (-0.25 kJ/min). During high dose A, plasma adrenaline correlated with increments in metabolic heat production (p < 0.05). Heart rate increased (p < 0.01) and diastolic blood pressure decreased (p < 0.01) at low dose A, and systolic blood pressure increased during intermediate dose A (p < 0.01). Forearm blood flow increased during A and C, with a greater increase in the former during high dose A (p < 0.01). Toe blood flow and toe pulp blood velocity decreased during high dose A (p < 0.05), whereas, skin capillary blood velocity increased at low (p < 0.05) and fell at high (p < 0.01) dose A. In summary, adrenaline increases metabolic heat production and limb blood flow in a dose-dependent fashion. A small increment in plasma adrenaline causes a rise in skin capillary blood flow; and at higher plasma levels blood flow in skin capillaries and arteriovenous anastomoses falls.

Dressler's syndrome presenting as acute pneumonitis.

An elderly man developed acute pneumonitis three weeks after a myocardial infarction treated with streptokinase. The differential diagnoses are discussed and a short review of lung disease in the post-myocardial infarction syndrome is presented.