Annika Rosengren

AIMS: The obesity paradox refers to the epidemiological evidence that obesity compared with normal weight is associated with counter-intuitive improved health in a variety of disease conditions. The aim of this study was to investigate the relationship between body mass index (BMI) and mortality in patients with acute coronary syndromes (ACSs). METHODS AND RESULTS: We extracted data from the Swedish Coronary Angiography and Angioplasty Registry and identified 64 436 patients who underwent coronary angiography due to ACSs. In 54 419 (84.4%) patients, a significant coronary stenosis was identified, whereas 10 017 (15.6%) patients had no significant stenosis. Patients were divided into nine different BMI categories. The patients with significant stenosis were further subdivided according to treatment received such as medical therapy, percutaneous coronary intervention (PCI), or coronary artery by-pass grafting. Mortality for the different subgroups during a maximum of 3 years was compared using Cox proportional hazards regression with the lean BMI category (21.0 to <23.5 kg/m(2)) as the reference group. Regardless of angiographic findings [significant or no significant coronary artery disease (CAD)] and treatment decision, the underweight group (BMI <18.5 kg/m(2)) had the greatest risk for mortality. Medical therapy and PCI-treated patients with modest overweight (BMI category 26.5-<28 kg/m(2)) had the lowest risk of mortality [hazard ratio (HR) 0.52; 95% CI 0.34-0.80 and HR 0.64; 95% CI 0.50-0.81, respectively]. When studying BMI as a continuous variable in patients with significant CAD, the adjusted risk for mortality decreased with increasing BMI up to ~35 kg/m(2) and then increased. In patients with significant CAD undergoing coronary artery by-pass grafting and in patients with no significant CAD, there was no difference in mortality risk in the overweight groups compared with the normal weight group. CONCLUSION: In this large and unselected group of patients with ACSs, the relation between BMI and mortality was U-shaped, with the nadir among overweight or obese patients and underweight and normal-weight patients having the highest risk. These data strengthen the concept of the obesity paradox substantially.

Summary Uncertainty exists regarding the relation of body size and weight change with dementia risk. As populations continue to age and the global obesity epidemic shows no sign of waning, reliable quantification of such associations is important. We examined the relationship of body mass index, waist circumference, and annual percent weight change with risk of dementia and its subtypes by pooling data from 19 prospective cohort studies and four clinical trials using meta‐analysis. Compared with body mass index–defined lower‐normal weight (18.5‐22.4 kg/m 2 ), the risk of all‐cause dementia was higher among underweight individuals but lower among those with upper‐normal (22.5‐24.9 kg/m 2 ) levels. Obesity was associated with higher risk in vascular dementia. Similarly, relative to the lowest fifth of waist circumference, those in the highest fifth had nonsignificant higher vascular dementia risk. Weight loss was associated with higher all‐cause dementia risk relative to weight maintenance. Weight gain was weakly associated with higher vascular dementia risk. The relationship between body size, weight change, and dementia is complex and exhibits non‐linear associations depending on dementia subtype under scrutiny. Weight loss was associated with an elevated risk most likely due to reverse causality and/or pathophysiological changes in the brain, although the latter remains speculative.

Background: Incidence rates of cardiomyopathies, which are a common cause of heart failure in young people, have increased during the last decades. An association between body weight in adolescence and future cardiomyopathy among men was recently identified. Whether or not this holds true also for women is unknown. The aim was therefore to determine whether for young women being overweight or obese is associated with a higher risk of developing cardiomyopathy. Methods: This was a registry-based national prospective cohort study with data collected from the Swedish Medical Birth Register, 1982 to 2014, with up to 33 years of follow-up. Included women were of childbearing age (18–45 years) during the initial antenatal visit in their first or second pregnancy (n=1 393 346). We obtained baseline data on body mass index (BMI), smoking, education, and previous disorders. After exclusions, mainly because of previous disorders, the final sample was composed of 1 388 571 women. Cardiomyopathy cases were identified by linking the Medical Birth Register to the National Patient and Cause of Death registers. Results: In total, we identified 1699 cases of cardiomyopathy (mean age at diagnosis, 46.2 [SD 9.1] years) during the follow-up with an incidence rate of 5.9 per 100 000 observation years. Of these, 481 were diagnosed with dilated cardiomyopathy, 246 had hypertrophic cardiomyopathy, 61 had alcohol/drug-induced cardiomyopathy, and 509 had other forms. The lowest risk for being diagnosed with a cardiomyopathy was detected at a BMI of 21 kg/m 2 , with a gradual increase in risk with higher BMI, particularly for dilated cardiomyopathy, where a hazard ratio of 4.71 (95% CI, 2.81–7.89) was found for severely obese subjects (BMI ≥35 kg/m 2 ), as compared with BMI 20 to &lt;22.5. Conclusions: Elevated BMI among young women was associated with an increased risk of being diagnosed with a subsequent cardiomyopathy, especially dilated cardiomyopathy, starting already at mildly elevated body weight, whereas severe obesity entailed an almost 5-fold increase in risk. With the increasing numbers of persons who are overweight or obese, higher rates of cardiomyopathy can be expected in the future, along with an altered disease burden related to adiposity.

BackgroundObesity is a predominant factor in development of type 2 diabetes but to which extent adolescent obesity influences adult diabetes is unclear. We investigated the association between body mass index (BMI) in young men and subsequent type 2 diabetes and how, in diagnosed diabetes, adolescent BMI relates to glycemic control and diabetes complications.MethodsBaseline data from the Swedish Conscript Register for men drafted 1968–2005 was combined with data from the National Diabetes and Patient registries. Diabetes risk was estimated through Cox regression and Kaplan-Meier survival estimates. Relationships between BMI, glycemic control and diabetes complications were assessed through multiple linear and logistic regression.FindingsAmong 1,647,826 men, 63,957 (3·88%) developed type 2 diabetes over a median follow-up of 29.0 years (IQR[21.0–37.0]). The risk of diabetes within 40 years after conscription was nearly 40% in individuals with adolescent BMI ≥35 kg/m2. Compared to BMI 18·5–<20 kg/m2 (reference), diabetes risk increased in a linear fashion from HR 1·18(95%CI 1·15–1·21) for BMI 20–<22·5 kg/m2 to HR 15·93(95%CI 14·88–17·05) for BMI ≥35 kg/m2, and a difference in age at onset of 11·4 years was seen. Among men who developed diabetes, higher adolescent BMI was associated with higher HbA1c levels and albuminuria rates.InterpretationRising adolescent BMI was associated with increased risk of type 2 diabetes diagnosed at a younger age, with poorer metabolic control, and a greater prevalence of albuminuria, all suggestive of worse prognosis.FundingThis work was supported by grants from the Swedish state under the agreement concerning research and education of doctors (ALFGBG-717,211, ALFGBG-881381); the Swedish Heart and Lung Foundation [Grant No. 2018-0366], the Swedish Diabetes Foundation; and the Swedish Research Council (2018-02527, VRREG 2019-00193).