Suoma E. Saarni

Sex Differences in Heritability of BMI: A Comparative Study of Results from Twin Studies in Eight Countries

Body mass index (BMI), a simple anthropometric measure, is the most frequently used measure of adiposity and has been instrumental in documenting the worldwide increase in the prevalence of obesity witnessed during the last decades. Although this increase in overweight and obesity is thought to be mainly due to environmental changes, i.e., sedentary lifestyles and high caloric diets, consistent evidence from twin studies demonstrates high heritability and the importance of genetic differences for normal variation in BMI. We analysed self-reported data on BMI from approximately 37,000 complete twin pairs (including opposite sex pairs) aged 20-29 and 30-39 from eight different twin registries participating in the GenomEUtwin project. Quantitative genetic analyses were conducted and sex differences were explored. Variation in BMI was greater for women than for men, and in both sexes was primarily explained by additive genetic variance in all countries. Sex differences in the variance components were consistently significant. Results from analyses of opposite sex pairs also showed evidence of sex-specific genetic effects suggesting there may be some differences between men and women in the genetic factors that influence variation in BMI. These results encourage the continued search for genes of importance to the body composition and the development of obesity. Furthermore, they suggest that strategies to identify predisposing genes may benefit from taking into account potential sex specific effects.

Association of Smoking in Adolescence With Abdominal Obesity in Adulthood: A Follow-Up Study of 5 Birth Cohorts of Finnish Twins

OBJECTIVES We studied the association of adolescent smoking with overweight and abdominal obesity in adulthood. METHODS We used the FinnTwin16, a prospective, population-based questionnaire study of 5 consecutive and complete birth cohorts of Finnish twins born between 1975 and 1979 (N = 4296) and studied at four points between the ages of 16 and 27 years to analyze the effect of adolescent smoking on abdominal obesity and overweight in early adulthood. RESULTS Smoking at least 10 cigarettes daily when aged 16 to 18 years increased the risk of adult abdominal obesity (odds ratio [OR]=1.77; 95% confidence interval [CI] = 1.39, 2.26). After we adjusted for confounders, the OR was 1.44 (95% CI = 1.11, 1.88), and after further adjustment for current body mass index (BMI), the OR was 1.34 (95% CI = 0.95, 1.88). Adolescent smoking significantly increased the risk of becoming overweight among women even after adjustment for possible confounders, including baseline BMI (OR = 1.74; 95% CI = 1.06, 2.88). CONCLUSIONS Smoking is a risk factor for abdominal obesity among both genders and for overweight in women. The prevention of smoking during adolescence may play an important role in promoting healthy weight and in decreasing the morbidity related to abdominal obesity.

Weight cycling of athletes and subsequent weight gain in middleage

Objective:To study the effects of repeated cycles of weight loss and regain as young adults on long-term weight development.Design:A follow-up study with questionnaires in 1985, 1995 and 2001.Setting:Finland.Subjects:A national cohort of 1838 male elite athletes who had represented Finland in major international sport competitions in 1920–1965, including 370 men engaged in sports in which weight-related performance classes are associated with weight cycling (boxers, weight lifters and wrestlers; further called as weight cyclers), and 834 matched control men with no athletic background.Outcome measure:Weight change since the age of 20 years, body mass index (BMI) and prevalence of obesity and overweight.Results:The weight cyclers gained 5.2 BMI units from age 20 years to their maximum mean weight, which was at age 58.7 years. Corresponding figures for the controls were 4.2 BMI units at 58.5 years and for other athletes 3.3 BMI units at age 62.5 years. The proportion of obese (BMI⩾30 kg/m2) subjects was greatest among the weight cyclers both in 1985 and 1995. In 2001, the weight cyclers were more often obese than other athletes, but did not differ from the controls. The odds ratio for the weight cyclers to be obese compared to other athletes in 1985 was 3.18 (95% confidence intervals 2.09–4.83), and compared to the controls 2.0 (1.35–2.96). The enhanced weight gain of the weight cyclers was not accounted for by present health habits (smoking, alcohol use, use of high-fat milk or physical activity) or weight at age 20 years.Conclusions:Repeated cycles of weight loss and regain appear to enhance subsequent weight gain and may predispose to obesity. Chronic dieting with weight cycling may be harmful for permanent weight control.

Body composition in psychotic disorders: a general population survey.

BACKGROUND The literature suggests an association between obesity and schizophrenia but fat mass and fat-free mass, which have been shown to be more predictive of all-cause mortality than only waist circumference and obesity [body mass index (BMI) 30 kg/m2], have not been reported in psychotic disorders. We examined the detailed body composition of people with different psychotic disorders in a large population-based sample. METHOD We used a nationally representative sample of 8082 adult Finns aged 30 years with measured anthropometrics (height, weight, waist circumference, fat percentage, fat-free mass and segmental muscle mass). Psychiatric diagnoses were based on a consensus procedure utilizing the Structured Clinical Interview for DSM-IV (SCID)-interview, case-notes and comprehensive register data. RESULTS Schizophrenia (including schizo-affective disorder) was associated with obesity [odds ratio (OR) 2.3, 95% confidence interval (CI) 1.5-3.6], abdominal obesity (waist circumference 88 cm for women, 102 cm for men) (OR 2.2, 95% CI 1.3-3.6) and with higher fat percentage (mean difference 3.8%, 95% CI 2.0-5.7%), adjusted for age and gender, than in the remaining sample. The associations between schizophrenia and low fat-free mass and decreased muscle mass on trunk and upper limbs became statistically significant after adjusting for BMI. After further adjusting for current antipsychotic medication, education, diet and smoking, schizophrenia remained associated with obesity (OR 1.9, 95% CI 1.1-3.6) and abdominal obesity (OR 3.8, 95% CI 1.5-9.4). Participants with affective psychoses did not differ from the general population. CONCLUSIONS Individuals with schizophrenia have metabolically unfavorable body composition, comprising abdominal obesity, high fat percentage and low muscle mass. This leads to increased risk of metabolic and cardiovascular diseases.

Inflammation in psychotic disorders: a population-based study.

We investigated inflammatory markers in psychotic disorders and their association with metabolic comorbidity, antipsychotic medication, smoking, alcohol use, physical condition, and mood. From the population-based Finnish Health 2000 study, we identified all persons with schizophrenia (n=45), other nonaffective psychosis (ONAP) (n=57), affective psychosis (n=37) and chose controls matched by age, sex, and region of residence. We found that persons with schizophrenia had significantly higher sIL-2Rα, IL-1RA and C-reactive protein (CRP), persons with ONAP significantly higher IL-1RA and CRP and persons with affective psychosis almost significantly higher TNF-α compared to their matched controls. Current antipsychotic use was associated with elevated IL-1RA and CRP. After taking metabolic and lifestyle-related variables that associated with inflammatory markers into account, only antipsychotic medication remained associated with elevated IL-1RA and TNF-α which are markers related to the activation of innate immune system. CRP was influenced by both antipsychotic medication and nonaffective psychosis. sIL-2Rα, a marker of T-cell activation, was associated with depressive symptoms, schizophrenia, and affective psychosis. We conclude that in persons with psychotic disorders, activation of mononuclear phagocyte system was mostly related to metabolic comorbidity and antipsychotic medication use, whereas T-cell activation had a more direct relationship with both psychotic disorders and depressive symptoms.

Mortality and its determinants in people with psychotic disorder.

Objective We investigated mortality and its determinants in people with psychotic disorder. Methods A nationally representative two-stage cluster sample of 8028 persons aged 30 years or older from Finland was selected for a comprehensive health survey conducted from 2000 to 2001. Participants were screened for psychotic disorder, and screen-positive persons were invited for a Structured Clinical Interview for DSM-IV. The diagnostic assessment of DSM-IV psychotic disorders was based on the Structured Clinical Interview for DSM-IV, case records from mental health treatments, or both. Mortality was followed up until September 2009 and analyzed using Cox proportional hazards model. Results People with schizophrenia (hazard ratio [HR] = 3.03; 95% confidence interval [CI] = 1.93–4.77) and other nonaffective psychoses (HR = 1.84; 95% CI = 1.17–2.91) had elevated mortality risk, whereas people with affective psychoses did not (HR = 0.61; 95% CI = 0.24–1.55). Antipsychotic medication use was associated with increased mortality (HR = 2.34; 95% CI = 1.86–2.96). There was an interaction between antipsychotic medication use and the presence of a psychotic disorder: antipsychotic medication use was only associated with elevated mortality in persons who were using antipsychotics and did not have primary psychotic disorder. In persons with psychotic disorder, mortality was predicted by smoking and Type 2 diabetes at baseline survey. Conclusions Schizophrenia and nonaffective psychoses are associated with increased mortality risk, whereas affective psychoses are not. Antipsychotic medication use increases mortality risk in older people without primary psychotic disorder, but not in individuals with schizophrenia. Smoking and Type 2 diabetes are important predictors of elevated mortality risk in persons with psychotic disorder.

Prevalence and correlates of major depressive disorder and dysthymia in an eleven-year follow-up – Results from the Finnish Health 2011 Survey

BACKGROUND Up-to-date epidemiological data on depressive disorders is needed to understand changes in population health and health care utilization. This study aims to assess the prevalence of major depressive disorder (MDD) and dysthymia in the Finnish population and possible changes during the past 11 years. METHODS In a nationally representative sample of Finns aged 30 and above (BRIF8901), depressive disorders were diagnosed with the Composite International Diagnostic Interview (M-CIDI) in 2000 and 2011. To account for nonresponse, two methods were compared: multiple imputation (MI) utilizing data from the hospital discharge register and from the interview in 2000 and statistical weighting. RESULTS The MI-corrected 12-month prevalence of MDD was 7.4% (95% CI 5.7-9.0) and of dysthymia was 4.5% (95% CI 3.1-5.9), whereas the corresponding figures using weights were 5.4% (95% CI 4.7-6.1) for MDD and 2.0% (95% CI 1.6-2.4) for dysthymia. Women (OR 2.33, 95% CI 1.6-3.4) and unmarried people (OR 1.54, 95% CI 1.2-2.0) had a higher risk of depressive disorders. There was a significant increase in the prevalence of depressive disorders during the follow-up period from 7.3% in 2000 to 9.6% in 2011. Prevalences were two percentage points higher, on average, when using MI compared to weighting. Hospital treatments for depressive disorders and other mental disorders were strongly associated with nonparticipation. LIMITATIONS The CIDI response rate dropped from 75% in 2000 to 57% in 2011, but this was accounted for by MI and weighting. CONCLUSIONS Depressive disorders are a growing public health concern in Finland. Non-participation of persons with severe mental disorders may bias the prevalence estimates of mental disorders in population-based studies.

Validation of the Finnish version of the SCOFF questionnaire among young adults aged 20 to 35 years

BackgroundWe tested the validity of the SCOFF, a five-question screening instrument for eating disorders, in a general population sample.MethodsA random sample of 1863 Finnish young adults was approached with a questionnaire that contained several screens for mental health interview, including the SCOFF. The questionnaire was returned by 1316 persons. All screen positives and a random sample of screen negatives were invited to SCID interview. Altogether 541 subjects participated in the SCID interview and had filled in the SCOFF questionnaire. We investigated the validity of the SCOFF in detecting current eating disorders by calculating sensitivity, specificity, and positive and negative predictive values (PPV and NPV) for different cut-off scores. We also performed a ROC analysis based on these 541 persons, of whom nine had current eating disorder.ResultsThe threshold of two positive answers presented the best ability to detect eating disorders, with a sensitivity of 77.8%, a specificity of 87.6%, a PPV of 9.7%, and a NPV of 99.6%. None of the subjects with current eating disorder scored zero points in the SCOFF.ConclusionDue to its low PPV, there are limitations in using the SCOFF as a screening instrument in unselected population samples. However, it might be used for ruling out the possibility of eating disorders.

Prevalence and correlates of eating disorders among young adults in Finland

Abstract Background: This study investigated the epidemiology of eating disorders in a population-based sample of young adults. Method: A mental health questionnaire was sent to a nationally representative two-stage cluster sample of 1863 Finns aged 20–35 years. All screen-positives and a random sample of screen-negatives were invited to participate in a Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) interview. Case records from all lifetime mental health treatments were also obtained and were used to complement the diagnostic assessment. Results: The lifetime prevalence of anorexia nervosa, bulimia nervosa, eating disorder not otherwise specified and any eating disorder among women were 2.1%, 2.3%, 2.0% and 6.0%, respectively, while there was only one man with an eating disorder. Unlike other mental disorders, they are associated with high education. Of women diagnosed with lifetime eating disorder, 67.9% had at least one comorbid Axis I psychiatric disorder, most commonly depressive disorder. While 79.3% of women with lifetime eating disorder had had a treatment contact, only one third of persons with current eating disorder had a current treatment contact. Women whose eating disorder had remitted still experienced more psychological distress and had lower psychosocial functioning that women without lifetime Axis I disorders. Conclusion: Eating disorders are the fourth largest group of mental disorders among young women. They tend to be comorbid, often remain untreated and are associated with residual symptoms after the remission of eating disorder symptoms.

Ethical Issues of Obesity Surgery—a Health Technology Assessment

New surgical technologies may challenge societal values, and their adoption may lead to ethical challenges. Despite proven cost-effectiveness, obesity (bariatric) surgery and its public funding have been questioned on ethical arguments relating to, for example, the self-inflicted or non-disease nature of obesity. Our aim was to analyze the ethical issues relevant to bariatric surgery. A comprehensive health technology assessment was conducted on bariatric surgery for morbid obesity using the EUnetHTA method, including a fully integrated ethical analysis. The ethical arguments suggesting that obesity should not be surgically treated because it is self-inflicted were rejected. Medicalization of obesity may have both positive and negative effects that impact the various stakeholders differently, thus being difficult to balance. Informing bariatric surgery patients and actively supporting their autonomy is exceptionally important, as the benefits and harms of both obesity and bariatric surgery are complex, and the outcome depends on how well the patient understands and adheres to the life-long changes in eating habits required. Justice considerations are important in organizing surgical treatment of obesity, as the obese are discriminated against in many ways and obesity is more common in socioeconomically disadvantaged populations who might have problems of access to treatments. Obesity should be treated like other diseases in health care, and obesity surgery rationed like other cost-effective treatments. Positive actions to ensure patient autonomy and just access to surgical treatments may be warranted.