Disease and Economic Burden of Poor Metabolic and Weight Control in Type 2 Diabetes in Spain: A Systematic Literature Review

Abstract

Introduction: Poor metabolic control and excess body weight are frequently present in people with type 2 diabetes (PwT2D).

Methods: A systematic literature review was conducted to identify observational studies reporting clinical, economic, and health-related quality of life (HRQoL) outcomes associated with poor metabolic (according to HbA1c, blood pressure [BP] and low density lipoprotein cholesterol [LDL-C] levels) and/or weight control (defined by a body mass index [BMI] ≥ 30 kg/m²) in adults with T2D in Spain, including articles published in either Spanish or English between 2013 and 2022 and conference abstracts from the last 2 years.

Results: Nine observational studies were included in the analysis. Poor glycemic control (HbA1c ≥ 7%) was associated with cardiovascular disease (CVD), increased requirements for antidiabetic medications, higher and more frequent weight gain, a greater probability of hypoglycemia and dyslipidemia, and worse health-related quality of life (HRQoL). Uncontrolled BP in PwT2D was related with the presence of CVD, worse metabolic control, and higher BMI and abdominal perimeter values. Poor LDL-C control or dyslipidemia was associated with CVD, hypoglycemia, and elevated HbA1c and triglycerides levels. The presence of a BMI ≥ 30 kg/m² was related to CVD and hypoglycemia, a higher prevalence of metabolic syndrome and worse BP control. Direct medical costs were found to be higher in PwT2D when coexisting with HbA1c levels ≥ 7%, uncontrolled BP or obesity. Increased total costs, including productivity losses, were also detected in those who presented uncontrolled BP and a BMI ≥ 30 kg/m², and when poor weight control existed together with HbA1c ≥ 8% and poorly controlled BP.

Conclusion: Gathered evidence supports the high clinical, economic and HRQoL burden of poor metabolic and/or weight control in PwT2D in Spain and reinforces the importance of prioritizing its control to reduce the associated burden, at both the individual and healthcare system levels.

Keywords: Burden of illness; HbA1c; Obesity; Type 2 diabetes mellitus.

Fig. 1

PRISMA flow diagram depicting literature screening and inclusion process

Fig. 2

Risk of CVD, hypoglycemia and dyslipidemia in uncontrolled vs. controlled normal weight individuals with T2D in Spain. *Results for 8% ≥ HbA1c > 7% group compared to HbA1c controlled individuals with T2D (HbA1c < 7%). Additional comparisons also available: 9% ≥ HbA1c > 8% vs. HbA1c < 7%, OR = 1.5; HbA1c > 9% vs. HbA1c < 7%, OR = 2.2. † Risk of dyslipidemia in those with a BMI ≥  30 kg/m². Orozco Beltrán et al. 2022 found a higher risk of dyslipidemia (OR = 1.6) in those of normal weight (BMI < 30 kg/m²)

Fig. 3

Annual direct medical costs in uncontrolled vs. controlled normal weight individuals with T2D in Spain. Studies reporting total direct costs are included in this graph. The studies exhibited heterogeneity in the variables considered for calculating total direct cost. Alonso Morán et al. (2014) also analyzed the economic burden of uncontrolled HbA1c showing additional costs per person-year in different groups vs. HbA1c < 7% population: 7% < HbA1c ≤  8%, + 251.5€; 8% < HbA1c ≤  9%, + 561.8€; HbA1c > 9%, + 447.5€. Differences between controlled and not controlled subgroups were significant