Philip J Weston

Evidence of defective cardiovascular regulation in insulin-dependent diabetic patients without clinical autonomic dysfunction

(1) Autonomic dysfunction is a well recognised complication of diabetes mellitus and early detection may allow therapeutic manoeuvres to reduce the associated mortality and morbidity. We sought to identify early cardiovascular autonomic neuropathy using spectral analysis of heart rate and systolic blood pressure variability. (2) Thirty patients with Type 1 (insulin-dependent) diabetes mellitus (DM) and 30 matched control subjects were studied. In addition to standard tests of autonomic function, heart rate and systolic blood pressure variability were assessed using power spectral analysis. From the frequency domain analysis of systolic blood pressure and R-R interval, the overall gain of baroreflex mechanisms was assessed. (3) Standard tests of autonomic function were normal in both groups. Total spectral power of R-R interval was reduced in the Type 1 DM group for low-frequency (473 +/- 63 vs. 747 +/- 78 ms2, mean +/- S.E.M., P = 0.002) and high-frequency bands (125 +/- 13 vs. 459+/-90 ms2, P < 0.0001). Systolic blood pressure low-frequency power was increased in the diabetic group (9.3 +/- 1.2 vs. 6.6+/-0.7 mmHg2, P < 0.05). The low frequency/high frequency ratio for heart rate variability was significantly higher in the Type 1 DM patients (4.6+/-0.5 vs. 2.9+/-0.5, P = 0.002), implying a relative sympathetic predominance. When absolute powers were expressed in normalised units, these differences persisted. There were significant reductions in baroreceptor-cardiac reflex sensitivity in Type 1 DM patients compared to controls while supine (9.7+/-0.7 vs. 18.5 +/- 1.7 ms/mmHg, P < 0.0001) and standing (2.9+/-0.9 vs. 7.18+/-1.9 ms/mmHg, P < 0.001). (4) Spectral analysis of cardiovascular variability detects autonomic dysfunction more frequently in Type 1 DM patients than conventional tests, and is suggestive of an abnormality of parasympathetic function. The abnormality of baroreceptor-cardiac reflex sensitivity could be explained by this impairment of parasympathetic function and this may predispose to the development of hypertension and increase the risk of sudden cardiac death. Using spectral analysis methods may allow detection of early diabetic cardiac autonomic neuropathy and allow therapeutic intervention to slow the progression.

Effects of GH replacement on 24-h ambulatory blood pressure and its circadian rhythm in adult GH deficiency.

objective Increased prevalence of hypertension and cardiovascular mortality have been reported in hypopituitary patients who had been appropriately replaced with conventional pituitary hormones except GH. Growth hormone replacement (GHR) results in improvement of surrogate markers of cardiovascular function. Data on effects of GHR on blood pressure (BP) in adult growth hormone deficiency (AGHD), however, remain contradictory. There are as yet no reports on BP circadian rhythms in untreated or treated AGHD. Therefore, in a 12‐month follow‐up study, we evaluated the effects of GHR on ambulatory blood pressure (ABP) in AGHD patients.

Insulin-treated diabetes and driving: what is the patient’s knowledge of current regulations?

Our survey aimed to determine whether educational deficits exist regarding patients’ knowledge of current driving regulations. We surveyed 100 insulintreated diabetes patients using questionnaires in October 2008. Fifty-eight were male and 42 female. Mean age was 52.9 years, mean duration of diabetes 15.1 years and mean glycated haemoglobin A 1C 7.5%. Eighty-nine patients (89%) had notified the UK Driver and Vehicle Licensing Agency and 79 (79%) their insurance company of insulin treatment. Sixty-five patients (65%) said they would consider checking their capillary blood glucose levels before each driving episode. The mean length of time patients said they would consider rechecking their capillary blood glucose levels during long journeys was 2.8 hours and the median time they will consider waiting before resuming driving after a hypoglycaemic episode was 45 minutes. The mean capillary blood glucose level that patients said they would consider safe to drive with was 4.8 mmol/L. Thirty-five patients (35%) said they were unaware that driving was not permitted for at least 45 minutes after hypoglycaemia had resolved. We concluded that there were deficits in aspects of patients’ knowledge of current driving regulations. Br J Diabetes Vasc Dis 2010;10:31–34

A cost-benefit analysis of twice-daily consultant ward rounds and clinical input on investigation and pharmacy costs in a major teaching hospital in the UK.

Objectives Misuse of investigations, medications and hospital beds is costing the National Health Service (NHS) billions of pounds with little evidence that approaches centred on reducing overuse are sustainable. Our previous study demonstrated that twice-daily consultant ward rounds reduce inpatient length of stay and suggested a reduction in overuse of investigations and medications. This study aims to assess the impact of daily consultant ward rounds on the use of investigations and medications and estimate the potential cost benefit. Settings The study was performed on two medical wards in a major city university teaching hospital in Liverpool, UK, receiving acute admissions from medical assessment and emergency departments. Participants and intervention The total number of patients admitted, investigations performed and pharmacy costs incurred were collected for 2 years before and following a change in the working practice of consultants from twice-weekly to twice-daily consultant ward rounds on the two medical wards. Outcome measures We performed a cost-benefit analysis to assess the net amount of money saved by reducing inappropriate investigations and pharmacy drug use following the intervention. Results Despite a 70% increase in patient throughput (p<0.01) the investigations and pharmacy, costs per patient reduced by 50% over a 12-month period (p<0.01) and were sustained for the next 12 months. The reduction in investigations and medication use did not have any effect on the readmission or mortality rate (p=NS), whereas, the length of stay was almost halved (p<0.01). Daily senior clinician input resulted in a net cost saving of £336 528 per year following the intervention. Conclusions Daily consultant input has a significant impact on reducing the inappropriate use of investigations and pharmacy costs saving the NHS more than £650K on the two wards over a 2-year period.

Hearing loss and type 2 diabetes: is there a link?

Recent meta‐analysis has confirmed an association between hearing loss and diabetes. The cause remains uncertain and open to academic debate.