Quality of life

The impact of switching insulin on Quality of Life:

What mediates improvement in well-being?

Contact: T. Hajos 

Quality of Life (QoL) gained importance as a central treatment outcome in the past two decennia in both diabetes research and care, in addition to outcomes such as HbA1c, dyslipidemia and the development of short-term and long term complications. QoL is still becoming increasingly important within these fields. Diabetes care mostly consists of self-care. Due to the significant role of the patients self-care behaviours and hence patient-reported outcomes in diabetes mellitus (DM) patients, QoL is especially important in DM. An association between glycaemic control and QoL has previously been shown to be present. However, there are many factors that can mediate this relation. To date research is still inconclusive about to what extent these factors, such as a reduction in both the number and bothersomeness of diabetes-related complaints, complications, (fear of) hypoglycaemia, (fear of) weight gain, hormonal factors, energy, burden of treatment and personal factors, such as appraisal and coping mediate to the relation between an improvement in glycaemic control and an increase in QoL. The 'natural' progression of diabetes (beta-cell dysfunction) eventually leads to the fact that the majority of patients with type 2 diabetes cannot avoid insulin therapy to treat hyperglycaemia. While insulin has been shown to improve glycaemic control and the HbA1c, sadly, it can also bring unwanted negative consequences. For example, it has side effects; it is often associated with weight gain and hypoglycaemic episodes. Hypoglycaemia and fear of hypoglycaemia are important barriers in the achievement of a good glycaemic control that can hamper a good QoL. Two longitudinal observational multi-site studies have been conducted, aiming to predict QoL impact of various psychological factors that are related to glycaemic control. Both studies had a follow-up of 6-months, with measurement points at baseline, 3 and 6 months. Inclusion for both studies was from January 2005 until January 2008. The first study, SPIRIT, has been conducted in suboptimally controlled insulin-naïve adult type 2 DM patients (N=1063), recruited from 363 Dutch primary care practices. Patients were switched from oral medications to insulin Glargine in combination with a rapid-acting insulin analog, oral medication, or both or two oral medications at baseline. In the second study, ESPRIT, a population of 821 suboptimally controlled type 2 DM patients using insulin were recruited from 116 out-patient clinics in the Netherlands . Patients were switched insulin Glargine in combination with a rapid-acting insulin analog or oral medication at baseline. In both studies, the treating doctor decided to switch their patients to insulin Glargine (care as usual).

Measures in both studies included demographic variables (age, gender, time since diagnosis, education level BMI and co-morbidity), glycaemic variables (HbA1c, fasting blood glucose, number of mild, nocturnal and severe hypoglycaemia during the past month), the WHO-5 well-being index (WHO-5), the Diabetes Symptom Checklist (DSC-r) and the worry subscale of the Hypoglycemia Fear Survey (HFS-W). The relation between all glycaemic measures, psychological variables and QoL will be studied longitudinally using GEE analysis. 

T.Hajos, MSc