Complications in type 2 diabetes - Biomarkers versus patients' thoughts and experiences

Activity: Examination and supervisionSupervision of PhD students


Background: The prevalence of diabetes mellitus type 2 and its complications is rising and it is still partially unknown which patients are at highest risk. Changing lifestyle and taking advice from health care could be challenging for the patients.

Objectives: The aim of this thesis was to study the association between the biomarkers C-peptide and copeptin and cardiovascular complications, death and changes in clinical outcomes in patients with type 2 diabetes. Moreover to explore patients’ thoughts and experiences regarding their diabetes diagnosis and its consequences.

Methods: Study I–III included 460 patients with type 2 diabetes diagnosed 1996-1998 from the Skaraborg Diabetes Register. Data on morbidity and mortality from National registers was linked to data from the patients’ medical charts. Cox regression analyses and logistic and linear regressions were used to study the associations between the biomarkers C-peptide and copeptin and clinical characteristics as predictors and cardiovascular complications and treatment as outcomes. Study IV was a qualitative interview study inspired by Malterud. Twelve patients diagnosed with diabetes in the last year were interviewed using a semi-structured interview guide. The analysis was conducted by systematic text condensation starting with identifying meaning units and preliminary themes and continuing with defining final categories and themes.

Results: Study I: Patients in the highest quartile of C-peptide concentrations had a 2.75-fold higher risk of death from all causes compared with those in the lowest quartile (95% CI = 1.17–6.47). Study II: Elevated copeptin concentrations were associated with development of chronic kidney disease (CKD) stage 3 (OR = 1.78, 95% CI = 1.01–3.16). Study III: High Body Mass Index (BMI) at diagnosis and smoking were associated with poorer treatment outcome (reduction of HbA1c) after 5 years. A high HbA1c at diagnosis predicted a greater reduction of HbA1c and initiation of insulin treatment. C-peptide and copeptin were not associated with an increase of blood pressure, HbA1c, BMI or insulin treatment. Study IV: Themes identified were Reaction to diagnosis, Life changes and Concerns about the future. The majority of patients reacted quite neutrally to the diagnosis. Lifestyle changes were mainly accepted but hard to achieve. When asked patients expressed some concerns about future practical consequences in daily life. Patients’ concerns differed from what most doctors focus on. It varied how much the patients wanted to know about their future risks.

Conclusions: High C-peptide and copeptin concentrations at diagnosis might identify patients at high risk for diabetic complications for whom individualized intensive treatment of all risk factors should be considered. Patients who smoke and have a high BMI should get advice on lifestyle and more intensive glucose lowering treatment. The patients and the doctors focus on different areas with regards to the problems of diabetes and there are important differences in the patients’ need for information which highlight the need for individualized care.
Period20132018 Apr 6
Examinee/Supervised personMiriam Pikkemaat
Examination/Supervision held at
Degree of RecognitionInternational