J. B. Ferriss

Prevalence and management of hypertension in Type 1 diabetes mellitus in Europe: The Eurodiab IDDM Complications Study

Aim To examine the prevalence of hypertension and the rates of hypertension awareness by investigating treatment and control among respondents to the EURODIAB IDDM Complications Study, and to explore the variation in hypertension management by age, sex and end‐organ damage.

Reduced plasma aldosterone concentrations in randomly selected patients with insulin-dependent diabetes mellitus.

Abnormalities of the renin‐angiotensin system have been reported in patients with diabetes mellitus and with diabetic complications. In this study, plasma concentrations of prorenin, renin, and aldosterone were measured in a stratified random sample of 110 insulin‐dependent (Type 1) diabetic patients attending our outpatient clinic. Fifty‐four age‐ and sex‐matched control subjects were also examined. Plasma prorenin concentration was higher in patients without complications than in control subjects when upright (geometric mean (95 % confidence intervals (CI): 75.9 (55.0–105.6) vs 45.1 (31.6–64.3) mU I‐1, p < 0.05). There was no difference in plasma prorenin concentration between patients without and with microalbuminuria and between patients without and with background retinopathy. Plasma renin concentration, both when supine and upright, was similar in control subjects, in patients without complications, and in patients with varying degrees of diabetic microangiopathy. Plasma aldosterone was suppressed in patients without complications in comparison to control subjects (74 (58–95) vs 167 (140–199) ng I‐1, p < 0.001) and was also suppressed in patients with microvascular disease. Plasma potassium was significantly higher in patients than in control subjects (mean ± standard deviation: 4.10±0.36 vs 3.89±0.26 mmol I‐1; p < 0.001) and plasma sodium was significantly lower (138 ± 4 vs 140 ± 2 mmol I‐1; p < 0.001). We conclude that plasma prorenin is not a useful early marker for diabetic microvascular disease. Despite apparently normal plasma renin concentrations, plasma aldosterone is suppressed in insulin‐dependent diabetic patients.

Blood pressure may be sodium-dependent in diabetic patients without overt nephropathy.

SummaryWe studied 29 normotensive diabetic patients free of long-term complications (13 insulin requiring and 16 noninsulin requiring), and 54 normotensive control subjects. No diabetic patient had overt nephropathy (in all 24 h urinary albumin excretion was <0.5G and Albustix was negative), but 24 h urinary albumin excretion was significantly higher than in control subjects in both insulin requiring and non-insulin requiring patients.Exchangeable sodium was increased in both insulin requiring and non-insulin requiring diabetic patients, compared with control subjects, and was similar in the two diabetic groups. Plasma renin activity was lower in non-insulin requiring patients than in control subjects, but was not different in insulin requiring patients and controls. Exchangeable sodium was significantly related to systolic and diastolic blood pressure in non-insulin requiring diabetic patients but was not related in insulin requiring patients or in control subjects. Exchangeablt sodium was positively related to 24 h urinary albumin excretion in each diabetic group.We conclude that sodium retention occurs in diabetic patients before the development of overt nephropathy. Recent evidence indicates that overt nephropathy is preceded by a phase of incipient nephropathy, when urinary albumin excretion is elevated and there is a small rise in blood pressure. The associations between body sodium and both blood pressure and 24 h urinary albumin excretion in non-insulin requiring diabetic patients suggest that blood pressure may become sodium dependent before the development of overt nephropathy in this group. This could contribute to the blood pressure rise in incipient nephropathy.

Hyperaldosteronism in ketoacidosis and in poorly controlled non-ketotic diabetes.

SummaryPLASMA aldosterone concentrations were measured in 14 patients in diabetic ketoacidosis and in 20 patients with poorly controlled non-ketotic diabetes, both before treatment and again when metabolic control was achieved. Plasma aldosterone was above normal in 12 of 14 patients in ketoacidosis and there was a highly significant fall in mean plasma aldosterone concentration when metabolic control improved. Plasma aldosterone concentration in ketoacidosis was significantly related to plasma angiotensin //, arterial pH and indirect indices of dehydration. Plasma aldosterone was also above normal before treatment in 7 of 20 patients with poorly controlled non-ketotic diabetes. When metabolic control improved there was a small but significant reduction in mean plasma aldosterone concentration. However, plasma aldosterone and angiotensin were not significantly related in these patients.It is concluded that ketoacidosis is usually associated with marked hyper-aldosteronism. Poorly controlled nonketotic diabetes is sometimes associated with mild aldosterone excess, which may contribute to the potassium wasting associated with poorly controlled diabetes.

Hypertension, hyperkalaemia and abnormalities of the renin-angiotensin system in diabetes mellitus.

SummaryBLOOD pressure levels are higher and hypertension is commoner among diabetics, compared with the nondiabetic population. Hypertension further increases mortality in diabetes, although it is not clear whether the effect is more marked than in normoglycaemic hypertensive subjects. Hypertension in the diabetic patient requires effective treatment.High levels of renin and angiotensin II occur in ketoacidosis, while low levels are seen in advanced diabetic nephropathy. There are conflicting data on renin levels in other diabetic conditions, including uncomplicated diabetes and diabetes associated with hypertension. We have shown that plasma angiotensin II falls with improved blood sugar control, and varying control might explain some of the differences between series.Isolated hypoaldosteronism in adults commonly results from a decreased production of renin and angiotensin II. Hypoaldosteronism presents with unexplained hyperkalaemia and appears to be associated with diabetes mellitus, especially in cases where renal function has been impaired, although a few such patients with normal renal function have been described. Our data indicate that overt hypoaldosteronism is rare among diabetics.In normal subjects plasma potassium usually falls following a glucose load. However, in some diabetic patients plasma potassium rises and this paradoxical response has been attributed to combined insulin-aldosterone deficiency. We report paradoxical hyperkalaemia in insulin-requiring diabetics without evidence of aldosterone deficiency. We also report paradoxical hyperkalaemia in a diabetic patient subsequently controlled by dietary restriction alone.

Premature hair greying may predict reduced bone mineral density in Graves’ disease

BackgroundPremature hair greying has been associated with low bone mineral density (BMD), and it may be more frequent in Graves’ disease.AimsTo determine whether premature greying is associated with reduced BMD in women with Graves’ disease and in control women, and to examine whether premature greying is more common in Graves’ disease.MethodsPremature greying (>50% grey by 40 years) and BMD were determined in 44 women with a history of Graves’ disease and 133 female controls referred for routine BMD measurement. Exclusion criteria included diseases or drugs known to affect BMD.ResultsMean Z and T scores at the lumbar spine were significantly lower (P<0.04) in subjects with premature greying than in those not prematurely grey among women with Graves’ disease, but not among control women. Multiple regression confirmed this difference between Graves’ and control women (P=0.041). There were no differences at other measurement sites. Of Graves’ patients, 36% were prematurely grey compared with 25% of control women (P=0.14).ConclusionPremature greying may be a weak marker for reduced BMD in women with a history of Graves’ disease, but it is not a marker in normal women.

Complications and cardiovascular risk factors in insulin-dependent diabetes--findings in an Irish clinic and in other European centres.

SummaryThe Eurodiab Insulin Dependent Diabetes (IDDM) Complications Study was a cross-sectional investigation of a stratified random sample of IDDM patients attending 31 clinics in 16 European countries. We compared the findings in the only participating Irish centre (Cork Regional Hospital) with those of the study group as a whole. There were fewer episodes of ketosis but severe hypoglycaemia occurred more frequently in Cork patients, when compared to the full study group. There were no significant differences in the prevalence of background retinopathy, proliferative retinopathy, microalbuminuria, macroalbuminuria or peripheral neuropathy, when the two groups were compared. However, autonomic neuropathy was significantly less common in Cork. The prevalence of cardiovascular disease was slightly lower than the Eurodiab average in Cork patients, and cardiovascular risk factors were more favourable. Waist-hip ratio and total plasma cholesterol were significantly lower than in the full study group. The prevalence of hypertension was similar, but there were fewer smokers in Cork than in most other centres

“Stokes’ Collar” due to a retrosternal toxic goitre

SummaryA 61 year old man had a large retrosternal goitre causing mediastinal compression, resulting in Stokes’ Collar and recurrent laryngeal nerve palsy. Following thyroidectomy, the mediastinal compression resolved and vocal cord function returned to normal.

Irish Endocrine Society: Proceedings of Annual Meeting held at St Vincents Hospital, Dublin, October 121h/13th, 1984.

LDL oxidation has been implicated as an important atherogenic factor. We have previously shown that the LDL estetified/free cholesterol ratio is different in diabetes. This study examines the effect ofLDL glycosylation on the susceptibility of LDL to in vitro oxidation. In particular it examines whether there is a relationship between LDL cholesterol esterification, LDL glycosylation and the susceptibility to oxidation. LDL was isolated by sequential ultracentrifugation from normoc holesternlaemic (n=l 0, serum cholesterol 5.30-+0.18mmol/ 1 ) and hypercholesterolaemic diabetic patients(n=7 serum cholesterol 7.18_+0.2mmol/1) and normocholesterolaemic control subjects (n=10, serum cholesterol 5.14_+0.28mmo1/1). LDL glycosylation was determined using aminophenylborate gel chromatography and LDL composition was determined. The susceptibility of LDL to oxidation in the presence of CuS04 was assessed by measuring thiobarbituric reactive substances (TBARS) LDL from the hypercholesterolaemic diabetic patients was more rapidly oxidised, TBARS at 1, 2, 3 and 4 hours being 12.6+3.7, 24.5+3.3, 38.4+2.3, and 40.0_+2.1 nmol/mg LDL protein compared with 4.8_+0.6,16.0+2.5, 24.5+9.5, and 32.4+2.1 for LDL from control subjects (p<0.05). Oxidation of LDL from the normocholeslerolaemic diabetic patients of 6.3_+0.7, 18.4=[_,0.3, 34.0+2.4 and 37.2+2.1, nmol/mg LDL protein, was also significantly greater than that from controls (p<0.05). The esterified/free cholesterol ratio correlated positively with the susceptibility of the LDL to oxidation (p<0.05) which was also related positively to the degree of LDL glycosylation (p<0.01). These results suggest a mechanism which would account for the increased accumulation of cholesterol in the atherosclerotic plaque of the normocholesterolaemic diabetic patient.