Clinical Features of Normal Weight Japanese Patients with Type 2 Diabetes who had Formerly been Obese

Abstract

Aim: Although the mean body mass index (BMI) of Japanese patients with type 2 diabetes was within the normal range, we have previously shown that approximately half of all patients classified as normal weight had been formerly obese. The present study examined the clinical features of Japanese type 2 diabetic patients who are currently of normal weight but had formerly been obese (NWFO). Methods: Body weight history with self-reported body weight was obtainable for 108 of 114 type 2 diabetic outpatients who had been regularly attending our department. Common carotid artery intima-media thickness (IMT) was also measured. Results: At the time of the examinations, 5 (5%) and 36 (33%) of 108 type 2 diabetic patients were lean (BMI 18.5 kg/m 2 ) and obese (BMI 25 kg/m 2 ), respectively, whereas normal weight (BMI ≥ 18.5-25 kg/m 2 ) was found in 67 (62%) patients. Among 108 patients, 67 (62%) were normal weight, of which 32 (48%) were formerly obese (NWFO). NWFO patients with a mean age of 65 years old at the clinic visit had reached their lifetime maximum body weight at age 45 and became diabetic at age 51 years. Obese patients aged 62 years at the clinic visit became diabetic at age 50 and had reached their maximum weight at age 51 years. Diabetes duration was 11 years in patients who had never been obese. Thus, NWFO patients had been exposed to obesity-related metabolic abnormalities and/or hyperglycemia for 20 years on average whereas obese and never obese patients had been exposed for 11-12 years. Although obese patients had higher fasting TG and greater BMI than NWFO, both obese and NWFO patients had similarly lower HDL cholesterol levels than those who had never been obese; however, there was no difference among the 3 groups in diabetic treatment, diabetes duration, HbA1c levels, and prevalence of atherosclerotic risk factors, including smokers, users of statins and antihypertensive drugs. Carotid max IMT was thicker in NWFO type 2 diabetic patients (0.86 0.04mm) than either obese patients (0.78 0.03mm, p 0.041) or those who had never been obese (0.78 0.02mm, p 0.046). Conclusion: This report confirms that approximately half of 108 Japanese type 2 diabetic patients who are currently normal weight were formerly obese and shows that these patients had a thicker carotid IMT than either obese patients or those who had never been obese. Formerly obese diabetic patients who have lost weight and are currently normal weight might have been exposed to long-term obesity-related cardiometabolic abnormalities and/or hyperglycemia, resulting in increased common carotid IMT. We therefore suggest that an improved clinical screening tool would include the assessment of body weight history for all Japanese type 2 diabetic patients at their first clinic visit.

Carotid Artery Plaque and LDL-to-HDL Cholesterol Ratio Predict Atherosclerotic Status in Coronary Arteries in Asymptomatic Patients with Type 2 Diabetes Mellitus

“…Carotid ultrasonography is useful to assess the extent of systemic atherosclerosis [16][17][18] . Increased carotid intima-media thickness (IMT), maximum-IMT in particular, is a strong predictor of future myocardial infarction 16) .…”

FTO Gene Polymorphism Is Associated with Type 2 Diabetes through Its Effect on Increasing the Maximum BMI in Japanese Men

“…The current BMI is a useful and convenient measure for the analyses, but it is questionable that the conditioning the association between FTO variants and T2D on current BMI could precisely evaluate the independency of the effect of FTO variants on T2D risk from their effects on influencing obesity/adiposity. In general, most subjects with T2D, especially those with East Asian ethnicity, reach their lifetime maximum BMI (BMI max ) before or at the time of the disease onset and, after the diagnosis of T2D, lifestyle interventions such as diet and exercise therapy, and/or treatments with some anti-diabetic medicines often influence their obesity related measures, such as BMI [21–23]. In many cases, the 'current BMI' was lower than BMI max , and as a result, the analyses using ‘current BMI’ might underestimate the effects of obesity/adiposity on conferring susceptibility to T2D, and overestimate the genetic effects of FTO variants on T2D risk, producing conflicting results regarding the association of FTO variants with T2D [24].…”

The long-term coronary heart disease risk of previously obese patients with type 2 diabetes mellitus

“…Accelerated atherosclerosis was more often observed in previously obese T2DM patients than in never-obese T2DM patients [11,12]. With the best possible medical care including the control of blood pressure and serum LDL cholesterol levels after enrollment, atherosclerosis progressed to coronary heart disease in previously obese patients.…”

“…Previously obese diabetic patients were likely to be associated with higher burden of atherosclerosis [11,12], but the long-term risk comparison of coronary heart disease between previously obese diabetic patients and never obese diabetic patients has not been examined in detail. The aim of the present study was to examine the effect of overweight/obesity before their first visit to a hospital on the long-term occurrence of coronary heart disease in patients with T2DM.…”