Factors that could explain the increasing prevalence of type 2 diabetes among adults in a Canadian province: a critical review and analysis.
BACKGROUND
The prevalence of diabetes has increased since the last decade in New Brunswick. Identifying factors contributing to the increase in diabetes prevalence will help inform an action plan to manage the condition. The objective was to describe factors that could explain the increasing prevalence of type 2 diabetes in New Brunswick since 2001.


METHODS
A critical literature review was conducted to identify factors potentially responsible for an increase in prevalence of diabetes. Data from various sources were obtained to draw a repeated cross-sectional (2001-2014) description of these factors concurrently with changes in the prevalence of type 2 diabetes in New Brunswick. Linear regressions, Poisson regressions and Cochran Armitage analysis were used to describe relationships between these factors and time.


RESULTS
Factors identified in the review were summarized in five categories: individual-level risk factors, environmental risk factors, evolution of the disease, detection effect and global changes. The prevalence of type 2 diabetes has increased by 120% between 2001 and 2014. The prevalence of obesity, hypertension, prediabetes, alcohol consumption, immigration and urbanization increased during the study period and the consumption of fruits and vegetables decreased which could represent potential factors of the increasing prevalence of type 2 diabetes. Physical activity, smoking, socioeconomic status and education did not present trends that could explain the increasing prevalence of type 2 diabetes. During the study period, the mortality rate and the conversion rate from prediabetes to diabetes decreased and the incidence rate increased. Suggestion of a detection effect was also present as the number of people tested increased while the HbA1cand the age at detection decreased. Period and birth cohort effect were also noted through a rise in the prevalence of type 2 diabetes across all age groups, but greater increases were observed among the younger cohorts.


CONCLUSIONS
This study presents a comprehensive overview of factors potentially responsible for population level changes in prevalence of type 2 diabetes. Recent increases in type 2 diabetes in New Brunswick may be attributable to a combination of some individual-level and environmental risk factors, the detection effect, the evolution of the disease and global changes.
Faculty of Medicine and Health Sciences, Université de Sherbrooke, 2500 boul. de l'Université, Sherbrooke, QC J1K 2R1 Canada ; Centre de formation médicale du Nouveau-Brunswick, 100 Des Aboiteaux St, Moncton, NB E1A 7R1 Canada.
Véronique
V
Thibault
Faculty of Medicine and Health Sciences, Université de Sherbrooke, 2500 boul. de l'Université, Sherbrooke, QC J1K 2R1 Canada ; Centre de formation médicale du Nouveau-Brunswick, 100 Des Aboiteaux St, Moncton, NB E1A 7R1 Canada ; Vitalité Health Network, 275 Main Street Suite 600, Bathurst, NB E2A 1A9 Canada ; 100 rue des Aboiteaux, Pavillon J.-Raymond Frenette, Moncton, NB E1A 3E9 Canada.
Mathieu
M
Bélanger
Faculty of Medicine and Health Sciences, Université de Sherbrooke, 2500 boul. de l'Université, Sherbrooke, QC J1K 2R1 Canada ; Centre de formation médicale du Nouveau-Brunswick, 100 Des Aboiteaux St, Moncton, NB E1A 7R1 Canada.
Emilie
E
LeBlanc
Faculty of Medicine and Health Sciences, Université de Sherbrooke, 2500 boul. de l'Université, Sherbrooke, QC J1K 2R1 Canada ; Centre de formation médicale du Nouveau-Brunswick, 100 Des Aboiteaux St, Moncton, NB E1A 7R1 Canada ; Vitalité Health Network, 275 Main Street Suite 600, Bathurst, NB E2A 1A9 Canada.
Lise
L
Babin
New Brunswick Department of Health, 520 King Street, Fredericton, NB E3B 6G3 Canada.
Stuart
S
Halpine
New Brunswick Department of Health, 520 King Street, Fredericton, NB E3B 6G3 Canada.
Beverly
B
Greene
New Brunswick Health Council, 100 des Aboiteaux Street, Suite 2200, Moncton, NB E1A 7R1 Canada.
Michelina
M
Mancuso
Diabetes mellitus; Epidemiology; Factors; Prevalence; Trends; Type 2 diabetes