Fat arms, obesity and choice of blood pressure cuff size in diabetic patients

Four hundred consecutive diabetic patients had their mid-arm circumference (AC) measured and body mass index (BMI) calculated to determine the proportion of an unselected clinic group who would require a larger than standard adult blood pressure (BP) cuff and whether or not BMI could be used to predict AC and hence choice of appropriate BP cuff size. More than 75% of both men and women had an AC > or = 29cm, justifying a larger than standard adult cuff for their BP measurement. When patients were classified according to their BMI, at least 80% with a BMI > or = 30 and more than 70% with a BMI of 25-29 had a measured AC > or = 29cm, while less than a third of patients with a BMI > or = 25 had an AC > or = 29cm. These results indicate that, in a diabetic clinic, most patients with a BMI > or = 25 are likely to require an alternative adult BP cuff if their blood pressure is to be measured precisely.

Ethnic origin and hypertension-associated alterations in sodium-lithium countertransport kinetics

In Caucasian subjects, elevated erythrocyte sodium-lithium countertransport (SLC) activity, displaying an increased affinity for external Na+ (decreased KNa), has a strong association with hypertension and has also been proposed as a potential marker for vascular disease. We have compared SLC activity and the kinetic components, KNa and maximal rate of turnover (Vmax), of the countertransporter in groups of Caucasian, Asian and Black hypertensive subjects matched for ethnicity, age and sex with healthy normotensive controls. SLC activity was the same in all ethnic groups irrespective of the presence of hypertension. Similarly, hypertension had no impact on Vmax values within each ethnic group (normotensive vs. hypertensives: Caucasian, 0.360 +/- 0.186 vs. 0.335 +/- 0.137; Asian, 0.324 +/- 0.078 vs. 0.273 +/- 0.105; black people, 0.192 +/- 0.123 vs. 0.178 +/- 0.082 mmol Li/l erythrocytes h). However, in black people compared with the other two ethnic groups, Vmax was lower for both controls and hypertensives (P < 0.05; ANOVA). Median KNa values in hypertensive subjects were consistently lower than their normotensive counterparts in all ethnic groups (P < 0.01; Kruskal-Wallis); Caucasians, (89.1 vs. 41.2 mmol Na; P = 0.01), Asians (121.1 vs. 33.1; P = 0.04) and black people (74.4 vs. 27.2 mmol Na; P = 0.02; Wilcoxon). The results show that Vmax is altered in black people independently of the presence of hypertension. This contrasts with KNa which, for each ethnic group studied, is reduced in the hypertensive compared with the normotensive state.

Association of angiotensin converting enzyme DD genotype with hypertension in diabetes

Angiotensin converting enzyme (ACE) genotypes have been associated with hypertension in the general population. However, the relation of ACE genotype to the prevalence of hypertension in diabetic populations is less clear. This study investigated ACE genotypes in 100 patients with diabetes mellitus, of whom 41 were on anti-hypertensive medication. A significant association was found between the presence of the ACE-D allele and hypertension in both the overall diabetic group (D = 0.66, P < 0.01) and in the subset of diabetics who had non-insulin-dependent diabetes (D = 0.69, P < 0.001). There was no correlation of ACE genotype with hypertension in insulin-dependent diabetes (D = 0.57).

Long-term safety of statin-fibrate combination treatment in the management of hypercholesterolaemia in patients with coronary artery disease

OBJECTIVE

To evaluate the long-term safety profile of treatment with a statin-fibrate combination in a cohort of patients with documented coronary artery disease.

DESIGN

Retrospective cohort analytical study.

SETTING

District general hospital.

PATIENTS

102 (81 male and 21 female) hypercholesterolaemic (total cholesterol concentration > 6.5 mmol/l) patients with documented coronary artery disease and who had been treated with a statin-fibrate combination for over 1 year. Coronary artery disease was confirmed by angiography in 93 patients and by a positive (Bruce protocol) exercise test in the remainder. Fifty eight patients had a history of previous coronary bypass graft surgery.

INTERVENTIONS

Twice daily lipid lowering treatment was given, with the fibrate administered in the morning (either bezafibrate 400 mg (n = 101) or fenofibrate 200 mg (n = 1)) and the statin in the evening (either simvastatin 10 mg (n = 23), 20 mg (n = 72), or 40 mg (n = 2) or pravastatin 10 mg (n = 1) or 20 mg (n = 4)). Treatment continued for 1 (n = 9), 2 (n = 58), or 3 (n = 35) years.

MAIN OUTCOME MEASURES

Selected laboratory variables (total cholesterol concentration and liver (aspartate transaminase (AST)) and muscle enzyme (creatine kinase (CK)) activities) and documented symptomatology.

RESULTS

A mean (SD) total cholesterol concentration of 5.2 (0.8) mmol/l was achieved after combined treatment for 1 year which was maintained at annual follow up. Over a maximum 3 year follow up no patient reported myalgic symptoms and none had a measured CK activity > 10 times above nomal. Four men on a simvastatin-bezafibrate combination had a CK activity rise to less than three times normal. Fourteen patients with a negative history of alcohol excess (consumption < 21 units/week) had borderline raised AST values.

CONCLUSIONS

Statin-fibrate combination treatment for up to 3 years in a cohort of patients with coronary artery disease was not associated with serious disturbances in biochemical markers of muscle or liver function.

Cholesterol-lowering drug therapy in a patient with receptor-negative homozygous familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is caused by mutations in the gene for the low density lipoprotein (LDL) receptor. It is generally believed that homozygous FH patients do not respond well to lipid-lowering drug therapy with inhibitors of 3-hydroxy-3-methylglutaryl CoA reductase because they cannot respond to an increased demand for hepatic cholesterol by up-regulation of LDL-receptor activity. In this paper we show that serum cholesterol in a homozygous FH patient with a receptor-negative LDL-receptor phenotype was reduced by 30% after treatment with simvastatin alone and by a further 11% with simvastatin in combination with probucol and nicotinic acid. The patient was a true homozygote, with two identical alleles of the LDL receptor gene in which a previously undescribed point mutation in exon 11 introduces a premature termination codon at residue 540 in the protein; the mutant protein is predicted to be truncated in the domain with homology to the epidermal growth factor precursor. Cultured cells from the patient were unable to bind, internalise or degrade LDL by the receptor pathway and there was no immunodetectable LDL receptor protein in the cells. Thus the lipid lowering effect of simvastatin in this individual must involve mechanisms other than stimulation of LDL receptors.

The effect of bezafibrate treatment on serum alkaline phosphatase isoenzyme activities

A reduction in serum total alkaline phosphatase (ALP) activity is a well-documented side effect of treatment with bezafibrate and other fibric acid derivatives. To evaluate the effect of bezafibrate treatment on individual ALP isoenzyme activities, 10 patients were studied on two separate occasions, first, after a 6-week period on no drug treatment, and second, after 6 weeks of bezafibrate therapy. On each occasion, serum total ALP and ALP isoenzyme activities and serum gamma-glutamyltransferase (GGT) activity were measured both after fasting and following the ingestion of a standardized high-fat meal rich in long-chain fatty acid triglycerides, as intestinal ALP activity is known to be influenced by dietary fat intake. Plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were measured on fasting samples. In the fasting state, bezafibrate treatment resulted in a 25% reduction (P < .01) in serum total ALP activity; liver ALP activity was reduced by 40% (P < .01), and biliary ALP activity was reduced in those patients in whom it was initially detectable, while bone and intestinal ALP activities were unchanged. There was also a 15% reduction (P < .05) in serum GGT activity, but no change in plasma AST or ALT activities. Serum intestinal ALP activity increased significantly (P < .01) by 1 hour following ingestion of the high-fat meal, but treatment with bezafibrate did not change the magnitude of this response. There was no change in the activity of any other ALP isoenzyme following fat ingestion. This study demonstrates that the effect of bezafibrate on serum ALP activity is confined to the liver and biliary isoenzymes.(ABSTRACT TRUNCATED AT 250 WORDS)

Triglyceride fatty acid chain length influences the post prandial rise in serum intestinal alkaline phosphatase activity

Intestinal alkaline phosphatase (IALP) activity rises following the ingestion of a fat-containing meal. Previous studies on intestinal fluid and lymph have shown that the magnitude of this response is dependent upon fatty acid chain length. To examine this relation in the serum of healthy humans, 10 subjects consumed two standardized fat meals. One meal contained predominantly long chain fatty acid triglycerides, the other contained predominantly medium chain fatty acid triglycerides. Serum IALP activity was measured in serial blood samples using a sensitive immunological assay. IALP activity was ABO blood group and secretor status dependent. The post-prandial rise in serum IALP activity was significantly greater following the long chain fatty acid meal than following the medium chain fatty acid meal. Previous observations of the fatty acid chain length dependency of the IALP response to fat ingestion, therefore, also apply in the serum of healthy humans under normal physiological conditions. Standardized fat meals provide the basis of a useful method for the investigation of the role of IALP in fat absorption.

Acute Changes in Haematological Parameters on Cessation of Smoking

Cigarette smoking is known to affect many haematological parameters but little is known of their rate of return to normal on withdrawal of cigarettes. Two groups of chronic smokers were studied whilst smoking and in the 2 weeks after cessation. A rapid return towards normal was found in the elevated haemoglobm concentration, packed cell volume, red cell count, white cell count, neutrophil count, lymphocyte count and platelet count, indicating that at least some of the abnormalities in these parameters are an acute, reversible effect of cigarette smoking rather than being a response to tissue damage.

Importance of Routine Measurement of HDL with Total Cholesterol in Diabetic Patients

The prevalence of hypercholesterolaemia and the frequency of a reduced HDL-cholesterol (at different cholesterol concentrations) were evaluated in a group of 400 diabetic patients attending a single diabetic clinic. Despite regularly supervised diabetes, including dietary advice, over one quarter of the patients had a serum total cholesterol concentration > 6.5 mmol/1, while over a quarter of the non-insulin treated and one eighth of the insulin treated diabetic subjects had an HDL-cholesterol <0.9 mmol/1, with a greater prevalence in the males compared with the females. More than 60% of all the diabetic patients who had a reduced HDL-cholesterol <0.9 mmol/1 also had a total cholesterol concentration <6.5 mmol/1. When the total/HDL-cholesterol ratio was calculated more non-insulin treated subjects had a value >4.5 as compared with insulin treated diabetic patients.

When comparisons were made between an age matched group of diabetic patients ( n=185) and a group of non-diabetic subjects attending for a health screen ( n=155), the frequencies of serum cholesterol concentrations greater than 5.2, 6.5, and 7.8 mmol/1 were similar for both groups. Significantly greater numbers of diabetic patients had a reduced HDL-cholesterol <0.9 mmol/1 (at any level of serum cholesterol) and a total/HDL cholesterol ratio >4.5.

This study has shown that the measurement of serum total cholesterol concentration alone will not characterize many subjects who are at risk of macrovascular complications due to a reduced HDL-cholesterol. As serum cholesterol and HDL-cholesterol can both be measured in the non-fasting state, routine measurement of HDL-cholesterol together with total cholesterol should be undertaken in all diabetic subjects and in other patient groups at high risk of cardiovascular disease.

Small bowel infarction mimicking Crohn's ileitis

A case of superior mesenteric arterial embolic occlusion with radiological features mimicking small bowel Crohn's disease is reported.

Steroid trials in the assessment of reversibility of air flow limitation: a survey of current clinical practice of chest physicians

To evaluate how steroid trials are currently used in the assessment of reversibility of air flow limitation, a postal questionnaire was sent to 355 consultant members of the British Thoracic Society working in England and Wales; 253 questionnaires were returned (71% response rate). Two respondents did not undertake steroid trials; of the remaining 251, 75% prescribed 30-40 mg oral prednisolone, with the commonest treatment period being 2 weeks. A high dose steroid inhaler was sometimes used as an alternative by 31% of respondents. Although 71% of respondents made lung function measurements on several occasions before starting steroids and 76% made measurements during treatment, 78% assessed patients on only one occasion at the end of the trials to ascertain its outcome. Weight, blood pressure and glycosuria were measured less frequently after the steroid treatment compared to the pre-trial period. Blood glucose and serum electrolytes were infrequently measured both before and after treatment. Wide variations exist in steroid trial regimens and current practice may neither provide definitive evidence of treatment benefit nor an adequate safeguard for patients against potential side-effects.

Doxazosin therapy in the treatment of diabetic hypertension

The incidence of cardiovascular disease in non-insulin-dependent diabetes mellitus (NIDDM) has not been reduced by the control of hyperglycemia alone. Hypertension and dyslipidemia may be the major determinants of macrovascular disease in these patients. With the high prevalence of hypertension in NIDDM, antihypertensive drugs are likely to be important determinants of an atherogenic lipid profile. To date, there is no completed major randomized controlled trial of antihypertensive treatment outcome in a diabetic population, and as such, drug choice for the treatment of diabetic hypertension is often based on evidence extrapolated from studies in nondiabetic groups. However, two short-term studies have assessed the effects of doxazosin antihypertensive therapy in subjects with NIDDM. Both studies showed that the significant reduction in blood pressure with doxazosin treatment was associated with favorable effects on the serum lipid profile. In one study, contrasting adverse effects of atenolol treatment on glycemic control, lipids, and lipoproteins were observed. Doxazosin therapy was associated with a trend toward correcting the disturbances of lipoprotein metabolism characteristic of NIDDM. These metabolic effects, combined with effective lowering of blood pressure by doxazosin, may be important determinants of cardiovascular disease in the long term.

Alpha-blocker therapy; a possible advance in the treatment of diabetic hypertension--results of a cross-over study of doxazosin and atenolol monotherapy in hypertensive non-insulin dependent diabetic subjects

Hyperglycaemia, a raised fibrinogen, an increased serum triglyceride and a reduced HDL-cholesterol are common metabolic features of non-insulin dependent diabetes mellitus (NIDDM). Hypertension is frequently associated with NIDDM, however the influence of antihypertensive therapy on these combined factors in the diabetic is at present unclear. In a double-blind placebo-controlled crossover study in 20 stable NIDDM subjects with hypertension, the metabolic effects of 6 weeks' treatment with the alpha-blocker, doxazosin, was compared with treatment with the beta-blocker, atenolol. Similar and significant reductions in BP were produced by both drugs. Significant increases in weight, HbA1, apoprotein B, serum triglyceride and cholesterol/HDL ratio were observed with atenolol therapy. Doxazosin therapy was associated with opposite patterns of changes in fasting glucose, lipids and lipoproteins but only for serum triglyceride was difference between treatments significant. Fibrinogen was not altered by either treatment. Conclusions from this study indicate; 1) adrenergic mechanisms may be an important influence on glucose homeostasis and lipid metabolism in NIDDM and 2) the beta-blocker, atenolol, has a small adverse effect on weight, glycaemic control and the atherogenic lipid profile, whereas the alpha-blocker, doxazosin, has no such effect and may, in part, correct the disturbances of lipoprotein metabolism characteristic of NIDDM.

Comparison of an immunochemical assay for plasma fibrinogen and a turbidimetric thrombin clotting technique to discriminate hyperlipidaemic patients from healthy controls

Plasma samples from patients attending a lipid clinic (n = 14) and healthy control subjects (n = 21) were assayed for fibrinogen using an immunochemical method (radial immunodiffusion) and a turbidimetric assay based on the thrombin clotting technique. The patients had significantly higher plasma fibrinogen concentrations than controls by both methods, but there was significant overlap between the two groups when fibrinogen was assayed by the thrombin clotting technique; there was almost complete separation of the two groups using the immunochemical assay. This difference in overlap could not be attributed to the presence or absence of fibrinogen degradation products. These findings may have important implications for the choice of method for determining plasma fibrinogen when assays are used for the assessment of cardiovascular risk. It is recommended that plasma fibrinogen should be assayed by both an immuno-chemical and a thrombin clotting method.

Sciatic nerve damage due to toilet seat entrapment: another Saturday night palsy

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Hypoglycaemia in an inner-city accident and emergency department: a 12-month survey

In a 12-month survey on the causes and frequency of hypoglycaemia presenting to an inner-city accident and emergency department, a total of 86 cases were recorded. A missed meal and/or alcohol ingestion accounted for most of the precipitating causes, being 52% and 21% respectively. As 49% of subjects presented with major clinical manifestations of hypoglycaemia (fit or coma), greater emphasis is required in the instruction on regularity of meal and caution with alcohol in high-risk groups such as the diabetic and also in non-diabetic groups.

Lipids, lipoproteins, and coronary heart disease: implications for antihypertensive therapy

There is now considerable evidence that treatment of abnormalities of lipids and lipoproteins reduces the incidence of coronary heart disease (CHD). Treatment of hypertension, another major cardiovascular risk factor, has not been shown to have the same impact on CHD. Possible explanations for this are that cardiovascular risk factors may occur in combination in an individual or that therapy for hypertension has adversely affected one or several of the other risk factors for CHD, thereby offsetting the benefit gained by lowering blood pressure. This article reviews the relationship between lipids, lipoproteins, and coronary heart disease, and the impact of cholesterol lowering on CHD. The evidence that antihypertensive drugs are associated with lipid and lipoprotein abnormalities is introduced by a critical appraisal of the several studies for such evidence. Implications for the treatment of the hypertensive patient are discussed.

Beta-blockers, lipoproteins and non-insulin dependent diabetes

In a study on 138 hypertensive non-insulin dependent diabetic subjects, factors influencing lipoproteins were assessed. Multiple regression analyses were carried out in order to assess the influence of beta-blocker antihypertensive therapy while making allowances for other confounding variables. In males, but not in females, on a beta-blocker for hypertension, total high density lipoprotein- (HDL-) and HDL-subfraction cholesterol were significantly lower while the serum triglyceride was increased, though not significantly. In male non-insulin dependent diabetics, regimens containing a beta-blocker may worsen an already abnormal lipoprotein profile and antihypertensive agents other than beta-blocking agents should be used if possible.

Acute lipoprotein changes associated with atenolol therapy for hypertension in non-insulin dependent diabetes

In a study on 11 stable hypertensive non-insulin dependent diabetic subjects the influence of beta-blocker (atenolol 100mg) withdrawal and reintroduction was assessed. After a three week placebo phase significant increases in pulse rate, high density lipoprotein- and high density lipoprotein2-cholesterol and a significant decrease in triglyceride were observed. Three weeks after recommencement of atenolol therapy the pulse, lipid and lipoprotein changes were reversed and significantly so. Weight and blood pressure remained constant throughout. Results from this study indicate that in non-insulin dependent diabetes, atenolol-induced lipid and lipoprotein changes are reversible in the short term and occur in the absence of significant changes in blood pressure control. The lipoprotein changes observed involved an alteration in high density lipoprotein composition. As a reduced high density lipoprotein cholesterol is associated with macrovascular disease, future studies on the association of lipoproteins and diabetic complications should take into account these changes in lipoproteins with beta-blocker hypotensive therapy.

Low-density lipoproteins increase intracellular calcium in aequorin-loaded platelets

Low-density lipoproteins activate isolated human platelets. The mechanism of this activation is unknown, but may involve increased phosphoinositide turnover. We have examined the effect of low-density lipoproteins on intracellular calcium concentrations in platelets loaded with the photoprotein aequorin. The lipoproteins induced concentration-dependent increases in intracellular calcium, associated with shape change and aggregation. These responses could be partially inhibited by the removal of extracellular calcium and by pre-incubation with acetylsalicylic acid. They were also antagonised by agents which increase cellular concentrations of cyclic adenosine and guanosine monophosphates. It is not clear whether the platelet-lipoprotein interaction involves a 'classical' lipoprotein receptor.

Diabetic hypertension--the importance of fibrinogen and blood viscosity

Fibrinogen and blood viscosity were measured in 72 stable non-insulin dependent diabetic subjects, 31 without hypertension, and 41 who had treated hypertension. The hypertensive group had higher plasma fibrinogen levels and blood viscosity. As both these rheological variables have been associated with micro- and macro-vascular disease, these findings may provide a possible explanation for the mechanism of the increased vascular disease seen in hypertensive compared with normotensive diabetic subjects.