No abstract

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.

A prevalence survey for known diabetes was conducted in a geographically defined population of nearly 40,100 in Oxford in April 1982. The age-adjusted prevalence rate was 10.4/1000 which did not differ significantly from age-adjusted rates of 9.5/1000 in Poole and 10.5/1000 in Southall. The prevalence increased with age and was higher in men than women over the age of 30 years. Our results confirm that there has been a change in the male to female sex ratio and suggest that there are about 500,000 diagnosed diabetics in England and Wales including about 190,000 insulin-treated patients. These findings are consistent with a secular increase in the prevalence of diagnosed diabetes over the last two decades which has important implications for the planning and provision of resources for care.

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.

Randomized controlled trials (RCTs) are the gold standard for evaluating treatment efficacy. Therefore, it is important that RCTs are conducted with methodological rigor to prevent biased results and report results in a manner that allows the reader to evaluate internal and external validity. Most human health journals now require manuscripts to meet the Consolidated Standards of Reporting Trials (CONSORT) criteria for reporting of RCTs. Our objective was to evaluate preharvest food safety trials using a modification of the CONSORT criteria to assess methodological quality and completeness of reporting, and to investigate associations between reporting and treatment effects. One hundred randomly selected trials were evaluated using a modified CONSORT statement. The majority of the selected trials (84%) used a deliberate disease challenge, with the remainder representing natural pathogen exposure. There were widespread deficiencies in the reporting of many trial features. Randomization, double blinding, and the number of subjects lost to follow-up were reported in only 46%, 0%, and 43% of trials, respectively. The inclusion criteria for study subjects were only described in 16% of trials, and the number of animals housed together was only stated in 52% of the trials. Although 91 trials had more than one outcome, no trials specified the primary outcome of interest. There were significant bivariable associations between the proportion of positive treatment effects and failure to report the number of subjects lost to follow-up, the number of animals housed together in a group, the level of treatment allocation, and possible study limitations. The results suggest that there are substantive deficiencies in reporting of preharvest food safety trials, and that these deficiencies may be associated with biased treatment effects. The creation and adoption of standards for reporting in preharvest food safety trials will help to ensure the inclusion of important trial details in all publications.