Prevalence of prediabetes and type 2 diabetes in two non-random populations aged 44-77 years in the Faroe Islands

Abstract

Aims: The prevalence of type 2 diabetes is increasing worldwide but little known about the status in the Faroe Islands. The aim was therefore to determine the prevalence of type 2 diabetes mellitus and prediabetes in two non-random populations aged 44-77 years.

Methods: This cross-sectional survey was conducted between 2011 and 2012 and included two sub-populations, namely 518 Septuagenarians aged 74-77 years (84% of the invited) and 401 Mark aged 44-73 years (87% of the invited). Subjects were screened for glycosylated haemoglobin, type A1c, non-fasting random plasma glucose, fasting plasma glucose followed by an oral glucose tolerance test. The screening was based on a diagnostic algorithm that included screening, diagnostic and confirmatory steps.

Results: Each group was analysed separately. In the Septuagenarian group 20.4% had type 2 diabetes, with 5.2% being newly detected and a total of 59% had prediabetes. In the Mark group 4.1% had diabetes, with 2.1% being newly detected and 22.3% had prediabetes. Diabetes increased with age and was significantly more prevalent among men. Women had lower mean fasting plasma glucose concentrations and men had lower values for 2-hours plasma glucose. Significant predictors associated with diabetes mellitus included obesity (BMI ≥ 30, abnormal waist/hip ratio and vegetable consumption.

Conclusions: Among the Faroese populations studied, the prevalence of type 2 diabetes increased with age and was more prevalent among men. The detected prevalence was comparable to other Nordic countries for all age-groups.

Keywords: 2hPG, 2-hour plasma glucose; BMI, body mass index; CDC, Centers for Disease Control and Prevention; Diagnostic criteria; FPG, fasting plasma glucose; Faroe Islands; HbA1c, glycosylated heamoglobin type A1c; IFG, impaired fasting glycaemia; IGT, impaired glucose tolerance; Impaired glucose regulation; K-T2D, Previously Known Type 2 Diabetes; M, Mark; N-T2D, newly diagnosed diabetes; NGT, normal glucose tolerance; OCP, organochlorine pollutant; OGTT, oral glucose tolerance test; Prediabetes; Prevalence; RPG, random plasma glucose; S, Septuagenarians; SD, standard deviation; T2D, type 2 diabetes; Type 2 diabetes mellitus; WHO, World Health Organization; WHR, waist/hip ratio.

Fig. 1

Protocol flow chart of the study population.

Fig. 2

The screening algorithm used in the Faroese Diabetes Study. ^aPercent were calculated from the entire screening group (n = 760). ^bEpidemiological DM was defined as a preliminary diagnosis of T2D. According to the screening program an initial screening confirmed the final diagnoses whether the subjects were diagnosed as being at low risk, having prediabetes or T2D (see boxes with broken lines).