Author(s): Alfrede Provilus 1 , Marie Abdallah 2 , Samy I McFarlane [[dagger]â ] 3
antidiabetic medications; insulin; sulfonylurea; thiazolidinedione; weight gain
Obesity in diabetic populations
Most people with Type 2 diabetes are either overweight or obese, with up to 90% of people with diabetes being overweight at diagnosis  . These patients continue to gain weight over time, with the exception of the postdiagnosis period where patients are educated and encouraged to lose weight for better control of their illness  . While risk factors for diabetes include increased age, hypertension, sedentary lifestyle, family history of diabetes and ethnic minorities (Box 1)  , obesity is one of the most important risk factors for insulin resistance, Type 2 diabetes and cardiovascular disease (CVD)  . Central obesity clusters with other cardiovascular risk factors in people with diabetes and is a major component of the metabolic syndrome [3,4] . CVD risk factors include insulin resistance, low high-density lipoprotein cholesterol, increased triglyceride levels, small dense low-density lipoprotein cholesterol, systolic hypertension, absence of nocturnal decline in pulse and blood pressure, increased oxidative stress and endothelial dysfunction, among others (Box 2) [3,4] .
A high prevalence of CVD risk factors associated with obesity has been demonstrated in large studies. In the Swedish National Diabetes Register, a cross-sectional analysis involving 44,042 Type 2 diabetes patients, with a 6-year prospective study of 4468 Type 2 diabetes patients, obese patients with diabetes (37%) had high frequencies of hypertension (88%) and hyperlipidemia (81%), as well as microalbuminuria (29%)  . Interestingly, control of blood pressure, a major risk factor for CVD in this population, to a goal of 130/80 mmHg was only achieved in 11% of patients  . Data for various ethnic minorities demonstrated a high prevalence of obesity and poor control of CVD risk factors in patients with diabetes [6,7] . In studies conducted in 2001 and 2004, less than 5% of diabetic patients achieved blood pressure, glycemic and lipid control simultaneously [6,7] .
Type 2 diabetes patients generally gain weight throughout the course of the disease. This weight gain is associated with worsening glycemic control and further increases CVD risk factors  . For example, in a follow-up study of 1292 women with coronary heart disease (CHD), higher levels of bodyweight within the 'ânormal'â range, as well as modest weight gain after 18 years of age, increased risks of CHD significantly, with a 5-â11 kg increase in bodyweight associated with a 25-â65% increase in CHD risk  . This risk is increased further with the aggregation of other CVD risk factors, such as hypertension and dyslipidemia associated with weight gain  . Weight gain has deleterious effects on glycemic control and other CVD risk factors, including hypertension and dyslipidemia, thus limiting the ability of the diabetic patients to comply with the treatment regimens  . Weight gain also sends mixed messages to the patients who are advised to lose weight as a major component of their treatment plan in order to gain better glycemic control.
Antidiabetic medications & weight gain
Major therapeutic classes of medications used for Type 2 diabetes, such as insulin,...