Programme no. 147-OP
A longitudinal study of diabetes mellitus
With special reference to incidence and prevalence, and to determinants of macrovascular complications and mortality
Kurt Svärdsudd1, Stefan Jansson*2, Dan Andersson3
1Department of Public Health and Caring Sciences, Uppsala University,Family Medicine and Preventive Medicine Section,Uppsala,Sweden, 2Allmänmedicinskt forskningscentrum,Institutionen för hälsovetenskap och medicin, Örebro universitet,Örebro,Sweden;Department of Public Health and Caring Sciences, Uppsala University,Family Medicine and Preventive Medicine Section,Uppsala,Sweden, 3Department of Public Health and Caring Sciences, Uppsala University,Family Medicine and Preventive Medicine Section,Uppsala,Sweden
* = Presenting author
Objectives: To investigate diabetes prevalence, incidence, mortality trends, the effects of hyperglycaemia and blood pressure, diabetes and hypertension treatment, and the effect of screening detection on total and CVD, myocardial infarction (MI) and stroke incidence.
Background: Diabetes affects 382 million people worldwide and is increasing in almost all countries. It is associated with excess morbidity and mortality, mostly owing to cardiovascular disease (CVD). Patients may have undetected type 2 diabetes for many years and at clinical diagnosis CVD risk factors and complications are already common. Consequently many organizations recommend screening for type 2 diabetes in high-risk individuals in order to prevent complications.
Results: During the study period 776 new diabetes cases was found, 36 type 1 diabetes mellitus and 740 type 2 diabetes mellitus. Age standardised incidence and prevalence rates for type 1 and type 2 diabetes did not increase over time. Diabetic patients had 17% higher mortality rate than non-diabetic persons, 22% in women,13% in men. The corresponding over-mortality in CVD was 33%, 41% in women and 27% in men. CVD mortality decreased across time in non-diabetic subjects and in diabetic men but not in diabetic women. Results regarding coronary heart disease (CHD) were similar. CVD incidence increased with fasting blood glucose (FBG), body mass index (BMI), mean arterial blood pressure (MABP), and decreased with metformin treatment and sulfonylurea. Myocardial infarction incidence increased with FBG, BMI and MABP, and decreased with metformin treatment. Stroke incidence increased with MABP. There was no difference in prognoses between those detected by screening or clinically.
Material/Methods: Between 1972 and 2001 all patients with diabetes, some detected clinically and some by case-finding procedures (screening), were entered in a diabetes register at Laxå Primary Health Care Center in Sweden. The register included information on medical treatment and laboratory data as well as information on mortality and morbidity from National Registers. The register was supplemented with five non-diabetic subjects, matched to each diabetes patients by age, sex, and year of detection.
Diabetes prevalence and incidence did not change over time. The over-mortality according to diabetes was moderate. CVD and MI during follow up were negatively affected by hypertension and hyperglycaemia, and positively by pharmacological diabetic treatment. For stroke no pharmacological protective effect was seen. Screening did not improve prognosis.
Points for discussion: What are the best options for treatment of patients with type 2 diabetes? Do we focus too much on glucose control vs other risk factors? Should we screen for diabetes as many organizations recommend?