Diabetes and the kidney
Diabetes mellitus is now one of the major causes of renal failure. The UK Renal Registry < www.renalreg.com> (which covered 72% of the UK adult population in 2001) reported that diabetic nephropathy was seen in 18% of new patients. This remains low in comparison to figures reported for Europe and USA. (22) Chronic renal failure is an important complication of diabetes as renal replacement carries a high morbidity and mortality especially in patients with diabetes. It also uses considerable health service resource.
Figure 25: Diabetes register: percentage recorded as having chronic renal failure
Note: Lanarkshire - data only available for secondary care. Shetland - no data submitted
Orkney - no data submitted
Figure 26: Comparison - Scotland 2001 & 2002. Number on register having end stage renal failure
It is difficult to compare figures in 2002 to those of last year's survey as the definition of chronic renal failure has been clarified and this could have resulted in reclassification of some individuals. The definition of chronic renal failure is taken to be: "Either serum creatinine was chronically greater than 500 mmol/l (i.e. >500 mmol/l on two occasions three months apart), or the patient was placed on permanent dialysis or received a renal transplant". The wide range between different boards is more likely to points to different stages of register development than to real differences in the prevalence of chronic renal failure.
Risk factors: Serum creatinine and urinary microalbumin
A recorded serum creatinine measurement was a new request for the diabetes survey this year. More than 60% of registered patients have had a creatinine measured within the last 15 months. This is a good start. We would anticipate a higher figure in next year's survey.
Figure 27: Diabetes register: Percentage with serum creatinine measured
Note: A&A - data excludes 53 patients who are under 12 years old. A&C - data is incomplete as one laboratory's data is missing. D&G - data is from out-patient clinic workloads only and does not include primary care diabetics. Orkney - no data submitted. W.l. - no data submitted
A recorded urinary microalbumin measurement was another addition to the diabetes survey in 2002. Microalbuminuria is defined by a rise in urinary albumin loss to between 30 and 300 mg/day. Urinary microalbumin screening is important in Type 1 diabetes as it indicates early diabetic renal disease. Intervention is believed to delay the deterioration of renal function. Microalbuminuria in Type 2 diabetes also indicates diabetic renal disease but is more important as a marker of increased risk of vascular disease. Aggressive management of vascular risk factors is required in this group of patients. A disappointing 22% of patients with diabetes have had a recorded urinary microalbumin assessment during the last 15 months. Assessment of urinary microalbumin is recommended by SIGN and is part of the Scottish Core Diabetes Dataset.
Figure 28: Diabetes register: percentage with urinary microalbumin measured
Note: A&A - data excludes 53 patients who are under 12 years old. D&G - data is from out-patient clinic workloads only and does not include primary care diabetics. Borders and Fife - data not submitted as only routinely screen type 1. Lanarkshire - data only available for secondary care. Orkney - no data submitted. W.l. - no data submitted
Diabetes and the heart
Diabetes Mellitus increases the relative risk of coronary death by 2.6 for women and 1.8 for men. In the 2002 Scottish Diabetes Survey, 8.1% of individuals are recorded as having had a myocardial infarction, 3.7% are recorded as having undergone previous cardiac revascularisation. The corresponding rates in the 2001 Survey were 6.7% and 2.1% respectively. The impression of the Monitoring Group is that the increased prevalence most probably reflects improved quality of diabetes registers nationally, thus an increase in ascertainment of these previous events has led to a better picture of the prevalence of these diseases across Health Boards. This is encouraging, as the figure of 8.1% is approaching that of 9.9% in Boards where there is validation of clinical diagnoses. In future years, we hope to look at the incidence rates of myocardial infarction and revascularisation, which are a better indicator of the effectiveness of primary and secondary preventative measures.
Figure 29: Diabetes register: percentage recorded as having had an MI
Note: Lanarkshire - data only available for secondary care. Shetland - no data submitted
Orkney - no data submitted
Figure 30: Comparison - Scotland 2001 & 2002. Number on register having had an MI
Figure 31: Diabetes register: percentage recorded as having undergone cardiac revascularisation
Note: Forth Valley - data is the sum of CABG & Angioplasty. Lanarkshire - data only available for secondary care. Shetland - no data submitted. Orkney - no data submitted
Figure 32: Comparison - Scotland 2001 & 2002. Number on register having undergone Cardiac revascularisation
Cardiac revascularisation was not tightly defined for this year's survey but is taken to mean all forms of revascularisation including stents and angioplasty.