Elsevier

Primary Care Diabetes

Volume 10, Issue 5, October 2016, Pages 329-333
Primary Care Diabetes

Original research
Trends in diabetes incidence from 1992 to 2015 and projections for 2024: A Portuguese General Practitioner's Network study

https://doi.org/10.1016/j.pcd.2016.05.003Get rights and content

Highlights

  • Diabetes incidence increased 4.29% per year, since 1992 to 2015 in Portugal.

  • The incidence rate projected for 2022–2024 was 972.77/105 inhabitants.

  • This represents the first study in Portugal about this issue.

  • This study could support public health goals aimed to reduce diabetes impact.

Abstract

Background

Diabetes is known as a major cause of morbidity and mortality worldwide. Portugal is known as the European country with the highest prevalence of this disease. While diabetes prevalence data is updated annually in Portugal, the General Practitioner's (GP) Sentinel Network represents the only data source on diabetes incidence. This study describes the trends in Diabetes incidence, between 1992 and 2015, and estimate projections for the future incidence rates in Portugal until 2024.

Methods

An ecological time-series study was conducted using data from GP Sentinel Network between 1992 and 2015. Family doctors reported all new cases of Diabetes in their patients’ lists. Annual trends were estimated through Poisson regression models as well as the future incidence rates (until 2024), sex and age group stratified. Incidence rate projections were adjusted to the distribution of the resident Portuguese population given Statistics Portugal projections.

Results

The average increase in Diabetes incidence rate was in total 4.29% (CI95% 3.80–4.80) per year under study. Until 1998–2000, the annual incidence rate was higher in women, and from 1998–2000 to 2013–2015 turn out to be higher in men. The incidence rate projected for 2022–2024 was 972.77/105 inhabitants in total, and 846.74/105 and 1114.42/105, respectively, in women and men.

Conclusions

This is the first study in Portugal to estimate diabetes incidence rate projections. The disturbing reported projections seem realistic if things continue as in the past. Actually, effective public health policies will need to be undertaken to minimize this alarming future scenario.

Introduction

Diabetes Mellitus (DM) is a chronic disease characterized by high levels of blood glucose, that develops either from the destruction of insulin-producing cells (type 1 diabetes) or when body tissues become resistant to the action of insulin, even in a state of circulating hyperinsulinemia (type 2 diabetes) [1]. Type 1 DM is an auto-immune condition that usually develops in childhood or adolescence, while type 2 DM develops in adulthood and is associated with obesity, physical inactivity and unhealthy diet. The latter represents 90% of the global cases of diabetes [2], [3].

DM is known as a major cause of morbidity and mortality worldwide, being one of the main responsible for the global burden of disease [4]. It is the leading cause of blindness, kidney failure and amputation worldwide [5], and is responsible for causing cardiovascular problems that lead to 50–80% of deaths in people with diabetes [6]. The prevalence of DM in Portugal in 2014 was estimated at 13.1% (10.8% in women and 15.8% in men) [7] and Portugal is known as the European Union country with the highest prevalence of this chronic disease [8].

While prevalence data is updated annually, based on the 2010 PREVADIAB nationwide study [9], and taking into consideration demographic changes, diabetes incidence has garnered less attention as a health indicator. The General Practitioner's (GP) Sentinel Network (GP Sentinel Network) represents, in Portugal, the only data source on diabetes incidence, since 1992 to nowadays.

Thus, this study aimed to gain insight into the DM incidence trends, between 1992 and 2015, in the Portuguese population under observation of the GP Sentinel Network, as well as to make projections for the future incidence rates based on this knowledge.

Section snippets

Methods

GP Sentinel Network is a network based on the volunteer work of General Practice/Family Medicine doctors whose professional activity is developed in primary healthcare centers of the Portuguese National Health System. These doctors report several health events, agreed each year. Between 1992 and 2015 (except 2001 and 2002), family doctors from GP Sentinel Network reported all new cases of DM (both types 1 and 2) in their patients’ lists. Diabetes case definition used was based on

Total and sex stratified incidence

In the first triennium under study, 1992–1994, the annual incidence rate was 261.7/105 inhabitants, and in the last triennium, 2013–2015, was 630.42/105 inhabitants (Fig. 1). Until 1998–2000, the annual incidence rate was higher in women, and from 1998–2000 to 2013–2015 turn out to be higher in men (Fig. 1).

The average increase in DM incidence rate was 4.29% (CI95% 3.80–4.80) per year under study. In men the annual trend was also of increase (5.16% [CI95% 4.47–5.86]) as well as in women,

Discussion

There was an increasing trend in the DM incidence in the time period under study, from 1992 to 2015. We propose that this increase can be related with three main possible reasons that could be acting jointly or individually. On one hand, it could be associated with an increase in the prevalence of obesity in Portugal [15], as obesity is known in the literature as one of the main risk factors for type 2 diabetes [5]. On the other hand, it could also be related with the increasingly pronounced

Conflict of interest

The authors declare no conflicts of interest.

Acknowledgments

The authors thank the volunteer work of General Practice/Family Medicine doctors from the GP Sentinel Network who provided information about incident cases of diabetes in their patients’ lists.

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