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.

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.

Glucose metabolism and thermogenesis during glucose and insulin infusion in severely underweight patients.

This study investigates the effects of gross loss of body weight on glucose disposal (GD), storage (GS), oxidation (GO), and the thermogenic response (TR) during hyperinsulinemic euglycemic glucose infusion in 9 underweight but nourished patients (UP) and in 3 of the patients after weight gain (WGP). In UP, baseline metabolic rate (MR) was 4.1 +/- 0.2 kJ/min and respiratory exchange ratio (RER) 0.97 +/- 0.02. During the final 30 minutes of hyperinsulinemia MR rose by 0.32 +/- 0.07 kJ/min (p less than .01) and RER rose to 1.09 +/- 0.03 (p less than .01). GD was 61 +/- 3 mumol/kg per minute, GO 35 +/- 1 mumol/kg per minute, and GS 26 +/- 4 mumol/kg per minute. The energy cost of glucose storage as glycogen was 0.15 kJ/min, and as lipid was 0.2 kJ/min. In WGP baseline MR was 4.5 +/- 0.4 kJ/min and RER was 0.91 +/- 0.03. During hyperinsulinemia MR rose by 0.63 +/- 0.2 kJ/min, RER rose to 0.93 +/- 0.02, GD was 53 +/- 4 mumol/kg per minute, GO was 30 +/- 3 mumol/kg per minute, and GS was 23 +/- 1 mumol/kg per minute. The energy cost for this glucose storage was 0.22 kJ/min. Therefore, during hyperinsulinemia in UP, GD, and TR are similar, but GO is greater and GS is less than previously reported in healthy subjects. However, this TR is entirely accounted for by the energy cost of glucose storage with no evidence of facultative thermogenesis. In WGP, all responses were similar to those in healthy subjects, and the TR was in excess of that required of the energy cost of glucose storage.

Junior doctors' on call activities: differences in workload and work patterns among grades.

OBJECTIVE: To examine the workload and work patterns of junior doctors of all grades while on call. DESIGN: Pilot study of activity data self recorded by junior doctors, with the help of students during busy periods. SETTING: A general surgical firm and a general medical firm based at University Hospital, Nottingham. SUBJECTS: Four registrars, three senior house officers, and five preregistration house officers. RESULTS: Senior house officers and preregistration house officers spent nearly half of all their on call duty time working, but less than half of that time was spent in direct contact with patients. Registrars were on call more often than the house officers but spent less than one fifth of their on call duty time working, and almost two thirds of that time was spent in direct contact with patients. CONCLUSIONS: Workload while on duty is excessive for both senior and preregistration house officers. Changes in some administrative procedures and employment of more non-medical staff during on call periods might reduce the time spent on non-clinical activities, thereby reducing the overall workload and allowing more time for patient contact.

Effect of two methods of hand heating on body temperature, forearm blood flow, and deep venous oxygen saturation.

Two methods of hand heating [warmed blanket 40 degrees C (WB) and warm-air box 55 degrees C (WA)] were compared with the effect of no heating (control) in six healthy females. After 30 min baseline, the left hand was either heated for 1 h or not heated. Measurements were made of skin temperature (ST), core temperature (CT), right forearm (FBF) and skin blood flow (SBF), and right forearm deep venous blood oxygen content with and without occlusion of the hand circulation. CT rose above baseline in WB (by +0.2 degrees C, P less than 0.01) but not with control or WA. Abdominal ST rose only with WB (by +0.66 degrees C above baseline, P less than 0.01). FBF increased above baseline values with both WA (by +10 ml.l forearm-1.min-1) and WB (by +12 ml.l forearm-1.min-1), but neither was significantly greater than the control. SBF increased above baseline only with WB (by +202 mV, P less than 0.01), and this was significantly greater than control SBF. With an occluded hand circulation, deep venous oxygen content rose above baseline values with WB only (+6.0%, P less than 0.01) but was not greater than control with either method of hand heating. We conclude that using a warm-air box has less effect than a heated blanket on the measured variables.

The effects of underfeeding for 7 d on the thermogenic and physiological response to glucose and insulin infusion (hyperinsulinaemic euglycaemic clamp).

The effect of underfeeding for 7 d (at 60 kJ/kg ideal body-weight) on the thermic and physiological responses to glucose and insulin infusions (hyperinsulinaemic euglycaemic clamp) was studied in six healthy women. Underfeeding had no significant effect on baseline metabolic rate, heart rate, forearm blood flow, diastolic blood pressure, blood intermediary metabolites, plasma insulin or catecholamines, but reduced both respiratory exchange ratio (RER; control (C) 0.86 (SE 0.02), underfed (U) 0.75 (SE 0.01); P less than 0.01) and systolic blood pressure (by approximately 10 mmHg, P less than 0.01). Baseline forearm glucose uptake and oxygen consumption were similar in both states. During the final 30 min of the glucose and insulin infusion, metabolic rate rose by 0.43 (SE 0.05) kJ/min in the C state, but no rise was seen in the U state (P less than 0.01). Glucose disposal rate (C 47.9 (SE 1.8), U 47.3 (SE 4.1) mumol/kg per min) and storage rate (C 27.5 (SE 2.4), U 31.6 (SE 3.6) mumol/kg per min) were similar in both states, but glucose oxidation rate was reduced in the U state (C 20.5 (SE 1.7), U 15.4 (SE 0.7) mumol/kg per min; P less than 0.05). RER rose to a higher value in the C state than in the U state (C 0.97 (SE 0.2), U 0.80 (SE 0.01); P less than 0.01). During hyperinsulinaemia, the forearm glucose uptake and O2 consumption rose in both states. No significant differences were seen in the cardiovascular responses to hyperinsulinaemia in either state. Thus underfeeding abolishes the rise in thermogenesis and reduces glucose oxidation during glucose and insulin infusions in healthy women, but does not affect the glucose disposal or storage rates or the other measured responses.

Effects of blood glucose concentration on thermogenesis and glucose disposal during hyperinsulinaemia.

1. The thermogenic and cardiovascular responses to glucose ingestion or infusion are altered by undernutrition. These changes may be due, in part, to alterations in the blood glucose concentration. This study investigates the effect of variation in the blood glucose concentration on the thermogenic and cardiovascular responses to a hyperinsulinaemic glucose clamp. 2. Ten healthy post-absorptive subjects (six male, aged 21-30 years) were studied on two occasions. Baseline measurements were made for 30 min, followed by a 90 min continuous insulin infusion (100 m-units min-1 m-2), during which the arterialized venous blood glucose concentration was maintained at 4.5 mmol/l (euglycaemia) or 3.5 mmol/l (mild hypoglycaemia). Measurements were made of glucose infusion rate and respiratory gas exchange from which glucose storage and oxidation and metabolic rate were calculated. 3. During the final 30 min of each hyperinsulinaemic clamp, the rates of glucose disposal (53.5 +/- 1.4 versus 38.2 +/- 1.0 mumol min-1 kg-1, P less than 0.01) and glucose storage (32.4 +/- 1.1 versus 22.8 +/- 1.2 mumols min-1 kg-1, P less than 0.05), and the increase in metabolic rate (0.44 +/- 0.08 versus 0.11 +/- 0.09 kJ min, P less than 0.01), were all greater with a blood glucose concentration of 4.5 mmol/l than of 3.5 mmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

The effect of a 48 h fast on the physiological responses to food ingestion in normal-weight women.

The thermogenic, cardiovascular and metabolic responses to a 30 kJ/kg body-weight test meal were studied in eight normal-weight, healthy female subjects after a 6 or 48 h fast. There was no significant change in metabolic rate following the 48 h fast, but plasma glucose, insulin, noradrenaline and respiratory exchange ratio were all reduced, and plasma beta-hydroxybutyrate was increased. Forearm blood flow was increased, with reduction in diastolic blood pressure. After the 48 h fast, there was a reduction in the metabolic rate response 40-90 min after food (control + 0.54 (SE 0.05), 48 h fast + 0.27 (SE 0.12) kJ/min, P less than 0.01), and in forearm blood flow and diastolic blood pressure responses, but increases in heart rate, blood glucose and plasma insulin responses to the ingestion of the test meal. There was no significant relationship between plasma catecholamine concentration and food ingestion or metabolic rate. Fasting induced considerable adaptation in these subjects and altered some of the physiological responses to food ingestion.

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.

The initial physiological responses to glucose ingestion in normal subjects are modified by a 3 d high-fat diet.

The present study was designed to investigate whether 3 d of high-fat, low-carbohydrate diet (with normal daily energy intake) affected the metabolic, cardiovascular and thermic responses to an oral glucose load (1.5 g/kg body-weight). Eight normal weight, healthy subjects (five male) consumed diets containing approximately 65% by energy of carbohydrate (C) or fat (F), each for 3 d. Before and after glucose ingestion, continuous recordings of oxygen consumption and carbon dioxide production were made using indirect calorimetry, and metabolic rate (MR) and respiratory exchange ratio (RER) were calculated. Heart rate, blood pressure and limb blood flow were also measured. There was no significant change in baseline MR following the high-fat diet, but the fasting RER was reduced. The high-fat diet modified the responses to oral glucose, with a greater increase in MR (kJ/min; C + 0.38, F +0.76), and an enhanced plasma insulin response (mU/l; C + 51.5, F + 85.0). There were no differences between the two diets with respect to the baseline blood glucose levels or the changes after glucose ingestion. Heart rate, systolic and diastolic blood pressures and blood flow responses to the glucose load were similar after the two diets. There was no plasma catecholamine response to glucose ingestion. It can be concluded that a high-fat diet alters the initial thermic response and insulin response but does not alter the other physiological responses to glucose ingestion.

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.

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.