Assay of microalbuminuria using gel electroimmunoassay

A population-based study of the incidence of complications associated with type 2 diabetes in the elderly

One hundred and eighty-eight known Type 2 diabetic patients aged over 60 years identified by a geographically based survey of a population of 40,076 were followed for a median of 6 years to determine the incidence of various complications. There were 63 deaths and two patients were lost to follow-up. The presence of complications was determined using a structured questionnaire and clinical examination. Incidence rates of ischaemic heart disease, stroke, and peripheral vascular disease (PVD) were 56 (95% CI 41-75), 22 (13-35), and 146 (117-174) 1000-person-years-1 of follow-up, respectively. Rates of stroke and PVD rose significantly with age. Retinopathy occurred at a rate of 60 (42-83) 1000-person-years-1 and cataract at 29 (17-46) 1000-person-years-1 although visual acuity in survivors did not deteriorate overall, probably reflecting the high mortality associated with cataract. The rate of proteinuria (albumin concentration greater than 300 mg l-1) was 19 (9-34) 1000-person-years-1. Incidence rates were unrelated to sex or duration of diabetes. Diabetes is associated with a continuing incidence of complications into old age. Adequate facilities are required to assess and treat the resulting morbidity in a population with an increasing proportion of elderly people.

Diabetes in the elderly: the Oxford Community Diabetes Study

Most diabetic patients are elderly but their clinical characteristics remain poorly defined. A population survey identified 259 known diabetic patients aged 60 years or more giving a prevalence of 3% in this age group. A total of 193 patients (75%) were interviewed and examined, 155 (80%) of whom had been diagnosed at under 70 years of age. Forty-two patients (22%) were insulin-treated but clinical characteristics suggested that at least 95% of all elderly patients had Type 2 diabetes. Blood glucose control was poor with median HbA1 9.7% (range 4.9-17.1%, normal reference range 5.0-7.5%), and 55% were either overweight or obese. There was a high morbidity from diabetes and other conditions: the prevalence of hypertension (untreated blood pressure of 160/95 mmHg or more or antihypertensive medication) was 52%, of stroke 5%, of nephropathy (urinary albumin concentration greater than or equal to 300 mg l-1) 3%, of lower limb amputations 4%, and of foot ulcers 7%. The prevalence of symmetrically impaired distal vibration perception was 23%, and 54% of patients either needed or were receiving chiropody. The prevalence of a corrected distant visual acuity of 6/12 or worse was 32% and of retinopathy of any degree was 26%. There was extensive co-morbidity which was not confined to a single subgroup of patients.

Diabetic autonomic neuropathy: the prevalence of impaired heart rate variability in a geographically defined population

The prevalence of diabetic autonomic neuropathy and its relationship with other diabetic complications were studied in a geographically defined population. Heart rate variability was measured by a computerized technique at rest and in response to both a single deep breath and a Valsalva manoeuvre. Among 43 Type 1 (insulin-dependent) and 202 Type 2 (non-insulin-dependent) patients results below the 2.5 centile for age-related normal ranges occurred in 9 Type 1 and 32 Type 2 patients (16.7, 95% Cl 12.6 to 21.9, %). Symptomatic autonomic neuropathy was uncommon but was significantly more frequent in Type 1 than Type 2 patients (5 Type 1, 1 Type 2, p less than 0.001 Fisher's exact test). In Type 1 diabetes, cardiovascular autonomic dysfunction was significantly associated with impaired vibration perception and a higher logarithmic urinary albumin concentration and, in Type 2 diabetes, it was associated with a significantly higher body mass index, systolic blood pressure, and logarithm of the urinary albumin and fasting insulin concentrations. The aggregation of these factors with cardiovascular autonomic dysfunction suggests that mortality might be increased in Type 2 patients with asymptomatic autonomic neuropathy.

Cerebral blood flow increases during insulin-induced hypoglycaemia in type 1 (insulin-dependent) diabetic patients and control subjects

The effect of insulin-induced hypoglycaemia on cerebral blood flow was examined using the intravenous xenon-clearance technique in 9 patients with Type 1 (insulin-dependent) diabetes (aged 20 to 43 years) and 9 age-matched control subjects before, during and after hypoglycaemia. Cerebral blood flow rose in both groups. The mean basal cerebral flood flow values were not significantly different and during hypoglycaemia mean cerebral blood flow increased by 17% (p = 0.008) in the diabetic patients and by 21% (p = 0.0003) in the control subjects. The results suggest that in young diabetic patients without autonomic neuropathy or microangiopathy cerebral vessels dilate normally in response to hypoglycaemia. The physiological importance of an increase in cerebral blood flow during hypoglycaemia is uncertain; but glucose availability is increased.