Anna-Maija Tolppanen

The Common Variant in the FTO Gene Did Not Modify the Effect of Lifestyle Changes on Body Weight: The Finnish Diabetes Prevention Study

The common single‐nucleotide polymorphism in the FTO (fat mass and obesity associated) gene is consistently associated with an increased risk of obesity. However, the knowledge of a potential modifying effect of the FTO gene on changes in body weight achieved by lifestyle intervention is limited. We examined whether the FTO gene variant (rs9939609, T/A) is associated with body weight and BMI and long‐term weight changes in the Finnish Diabetes Prevention Study (DPS). Altogether, 522 (aged 40–65 years; BMI ≥25 kg/m2) subjects with impaired glucose tolerance (IGT) were randomized to control and lifestyle intervention groups. SNP rs9939609 was genotyped from 502 subjects. At baseline, those with the AA genotype had higher BMI than subjects with other genotypes (P = 0.006). The association was observed in women (P = 0.016) but not in men. During the 4‐year follow‐up, the subjects with the AA genotype had consistently the highest BMI (P = 0.009) in the entire study population. The magnitude of weight reduction was greater in the intervention group, but the risk allele did not modify weight change in either of the groups. Our results confirm the association between the common FTO variant and BMI in a cross‐sectional setting and during the long‐term lifestyle intervention. We did not observe association between FTO variant and the magnitude of weight reduction achieved by long‐term lifestyle intervention. Based on the results from the DPS, it is unlikely that the common variant of the FTO gene affects the success of lifestyle modification on weight loss.

Midlife and late-life body mass index and late-life dementia: results from a prospective population-based cohort.

BACKGROUND Obesity has been consistently associated with dementia. The role of certain risk factors of dementia may change during life, and the importance of having a life-course perspective has been acknowledged. OBJECTIVE The aim of this study was to investigate the association of midlife and late-life body mass index (BMI) with late-life dementia/Alzheimers disease (AD) and whether the association was independent of other obesity-related co-morbidities. METHODS The association between midlife BMI (mean age 50.2, SD 6.0) and late-life BMI (mean age 71.2, SD 4.0) and incident dementia later in life (mean age 75.7, SD 5.0) were investigated among 1,304 participants of the longitudinal population-based Cardiovascular risk factors, Aging and Dementia (CAIDE) study, conducted in Eastern Finland. The duration of follow-up was 26 years. The diagnosis of dementia was based on DSM-IV criteria and the probable and possible AD on the NINCDS-ADRDA criteria. RESULTS Higher midlife BMI was associated with higher risk of incident dementia (adjusted HR, 95% CI 1.07, 1.00-1.14). However, decrease in BMI from midlife to late-life was associated with higher risk of dementia (1.14, 1.03-1.25 for one-unit decrease) and AD (1.20, 1.09-1.33). High late-life BMI was associated with lower risk of AD (0.89, 0.81-0.98) but the association with dementia was less evident (0.94, 0.86-1.03). CONCLUSION Higher midlife BMI is related to higher risk of dementia and AD, independently of obesity-related risk factors and co-morbidities. Steeper decrease of BMI and low late-life BMI are associated with higher risk of dementia and AD. These findings highlight the importance of life-course perspective when assessing the association between BMI and cognition.

Midlife Vascular Risk Factors and Alzheimer's Disease: Evidence from Epidemiological Studies

The shared risk factor profile between cardiovascular diseases and Alzheimers disease (AD), observations on vascular pathology in AD, and altered cerebral blood flow in AD brains have led to the suggestion that AD might be a vascular disorder with neurodegenerative consequences. Targeting vascular and metabolic risk factors could be an effective way to prevent AD. Higher body mass index, elevated blood pressure, serum cholesterol concentrations, and impaired glucose regulation have been associated with increased risk of AD. Interestingly, the associations between these factors measured at mid-life are stronger, or even opposite, than with the risk factors measured at late-life. This may reflect true differences in the association (i.e., mid-life risk factors being a better measure of vascular load during adulthood), reverse causality, or bias. The vascular risk factors can directly increase the susceptibility to AD, or the effect can be mediated via cardio- and cerebrovascular diseases.

Risk Factors for Variation in 25-Hydroxyvitamin D3 and D2 Concentrations and Vitamin D Deficiency in Children

CONTEXT Vitamin D status is believed to be best indicated by serum 25-hydroxyvitamin D [25(OH)D; consisting of 25(OH)D₃ and 25(OH)D₂] that are obtained from different sources. Suboptimal vitamin D status is common and associated with adverse health outcomes. OBJECTIVES The objectives were to report the prevalence and risk factors of vitamin D deficiency and determine associations of characteristics that have been shown to relate to total 25(OH)D with 25(OH)D₃ and 25(OH)D₂ concentrations. DESIGN AND SETTING The Avon Longitudinal Study of Parents and Children is a population-based contemporary birth cohort (children born in 1991-1992) from southwest England. PARTICIPANTS AND OUTCOME MEASURES Seven thousand five hundred sixty children with serum 25(OH)D₃ and 25(OH)D₂ concentrations measured at the mean age of 9.9 yr participated in the study. RESULTS Vitamin D deficiency [total 25(OH)D concentration <20 ng/ml] was common (29%). The main risk factors were winter season, less time spent outdoors, low socioeconomic position, nonwhite ethnicity, older age, more advanced puberty stage, and female gender. Although there were some common risk factors for lower 25(OH)D₃ and 25(OH)D₂ concentrations (age, gender, puberty stage, body mass index, physical activity, household income, maternal education), several characteristics were associated with 25(OH)D₃ only (ethnicity, vitamin D intake, time spent outdoors, and UVB protection score) and others with 25(OH)D₂ only (protein and carbohydrate intake, parents social class, and housing tenure). CONCLUSIONS Vitamin D deficiency was common in this contemporary U.K. cohort. Despite some overlap, there are differences in potential confounding structures for associations of 25(OH)D₃ and 25(OH)D₂ with health outcomes. These should be accounted for in future studies.

From prescription drug purchases to drug use periods – a second generation method (PRE2DUP)

BackgroundDatabases of prescription drug purchases are now widely used in pharmacoepidemiologic studies. Several methods have been used to generate drug use periods from drug purchases to investigate various aspects; e.g., to study associations between exposure and outcome. Typically, such methods have been fairly simplistic, with fixed assumptions of drug use pattern and or dose (for example, the assumed usage of 1 tablet per day). This paper describes a novel PRE2DUP method that constructs drug use periods from purchase histories, and verified by a validation based on an expert evaluation of the drug use periods generated by the method.MethodsThe PRE2DUP method is a novel approach based on mathematical modelling of personal drug purchasing behaviors. The method uses a decision procedure that includes each person’s purchase history for each ATC code, processed in a chronological order. The method constructs exposure time periods and estimates the dose used during the period by considering the purchased amount in Defined Daily Doses (DDDs), which is recorded in the prescription register database. This method takes account of stockpiling of drugs, personal purchasing pattern; i.e., regularity of the purchases, and periods of hospital or nursing home care where drug use is not recorded in the prescription register. The method can be applied to a variety of drug classes with different doses and use patterns by controlling restriction parameters for each ATC class, or even each drug package. In the presented example, the PRE2DUP method was applied to a register-based MEDALZ-2005 study cohort. All drug purchases (3,793,085) recorded in the Finnish prescription register between 2002 and 2009 for persons with Alzheimer’s disease (28,093) were included.ResultsResults of the expert-opinion based validation indicate that PRE2DUP method creates drug use periods with a relatively high correctness. Drugs with varying patterns of use and drugs used on a short-term basis only require more precise parameters.ConclusionsPRE2DUP method gives highly accurate drug use periods for most drug classes, especially those meant for long-term use.

High prevalence of psychotropic drug use among persons with and without Alzheimer's disease in Finnish nationwide cohort

Psychotropic drugs are used for treatment of behavioral and psychological symptoms of dementia (BPSD) although they are associated with serious adverse drug events. Objective of our study was to investigate prevalence of psychotropic drug use one year after diagnoses of Alzheimers disease (AD), to compare prevalence to persons without AD and to assess changes in prevalence over time. Data from the MEDALZ (Medication use and Alzheimers disease) cohort was utilized in the study including all 69,080 community-dwelling persons with new diagnosis of AD during years 2005-2011 in Finland. Four age-, gender- and region of residence-matched persons without AD were identified for each case. Register-based data included prescription drug purchases and comorbidities from Special Reimbursement Register. Annual prevalence of psychotropic drug use one year after diagnosis was determined for each person. Psychotropic drugs were used by 53% of persons with AD compared with 33% of persons without AD during one year after diagnoses. Persons with AD were six times more likely to use antipsychotics and three times more likely to use antidepressants whereas benzodiazepine and related drug (BZDR) use was comparable between persons with and without AD. According to year of AD diagnoses during 2005-2011, antipsychotic use increased from 18% to 20% (p<0.0001) and BZDR use declined from 31% to 26% (p<0.0001) among persons with AD. Widespread utilization of psychotropic drugs was observed among persons with AD. Despite safety warnings of antipsychotic use for BPSD, antipsychotic use increased from 2005 to 2011 among newly diagnosed persons with AD in Finland.

Impact of high risk drug use on hospitalization and mortality in older people with and without Alzheimer's disease: a national population cohort study.

Background Evidence is lacking about outcomes associated with the cumulative use of anticholinergic and sedative drugs in people with Alzheimer’s disease (AD). This retrospective cohort study investigated the relationship between cumulative exposure to anticholinergic and sedative drugs and hospitalization and mortality in people with and without AD in Finland. Methods Community-dwelling people aged 65 years and over, with AD on December 31st 2005 (n = 16,603) and individually matched (n = 16,603) comparison persons (age, sex, region of residence) were identified by the Social Insurance Institution of Finland. Drug utilization data were extracted from the Finnish National Prescription Register. Exposure to anticholinergic and sedative drugs was defined using the Drug Burden Index (DBI). Hospitalization and mortality data were extracted from national registers. Cox and zero-inflated negative binomial analyses were used to investigate the relationship between DBI and hospitalization and mortality over a one-year follow-up. Results In total, 5.8% of people with AD and 3.7% without AD died during 2006. For every unit increase in DBI, the adjusted hazard ratio for mortality was 1.21 (95% confidence intervals [CI]: 1.09–1.33) among people with AD, and 1.37 (95%CI: 1.20–1.56) among people without AD. Overall, 44.3% of people with AD and 33.4% without AD were hospitalized. When using no DBI exposure as the reference group, the adjusted incidence rate ratio for length of hospital stay among high DBI group (≥1) in people with AD was 1.15 (95%CI: 1.05–1.26) and 1.63 (95%CI: 1.41–1.88) in people without AD. Conclusion There is a dose-response relationship between cumulative anticholinergic and sedative drug use and hospitalization and mortality in people with and without AD.

Use of existing data sources in clinical epidemiology: Finnish health care registers in Alzheimer's disease research - the Medication use among persons with Alzheimer's disease (MEDALZ-2005) study.

Memory diseases are the most important determinant of health care service use and quality of life among older individuals. Adverse effects of medication are common among older people, but this age group is underrepresented in clinical trials. Finnish statutory health care and prescription registers, together with personal identification numbers (PINs) and a tax-supported public health plan covering all citizens provide excellent opportunities for epidemiological research. We used routinely collected data from the Finnish health care system to establish the Medication use among persons with Alzheimer’s disease (MedAlz-2005) cohort. This cohort study will be used to assess medication use and its effects on health status and hospitalization among persons with Alzheimer’s disease (Ad). The cohort includes all community-dwelling persons who had a clinically verified diagnosis of Ad, resided in Finland, and were alive on December 31, 2005 and a matched comparison person for each affected individual. data on purchased prescription medicines (1995–2009), inpatient hospital admissions (1972–2009), outpatient visits (1995–2009), details on diagnosed cancers (1972–2009), and mortality (until October 2010) are available for the whole cohort. This paper describes how this data can be utilized in etiological research and the assessment of health care service use, drug utilization, and associated adverse outcomes in a particularly vulnerable group that is often underrepresented in clinical trials.

Variation in the UCP2 and UCP3 genes associates with abdominal obesity and serum lipids: The Finnish Diabetes Prevention Study

BackgroundWe explored the associations of three variants in the uncoupling protein 2 (UCP2) gene, one variant in the UCP2-UCP3 intergenic region and five variants in the uncoupling protein 3 (UCP3) gene with obesity and diabetes related traits in subjects with impaired glucose tolerance participating in Finnish Diabetes Prevention Study. Altogether 507 overweight individuals (body mass index: 31.2 ± 4.5 kg/m2, age: 55 ± 7 years) for whom DNA was available were randomized to either an intensified diet and physical activity group or to a conventional care control group.MethodsWe analysed the data from the baseline and annual follow-up visits from years 1, 2 and 3. Measurements of anthropometry, plasma glucose and serum insulin in oral glucose tolerance test, serum total cholesterol, HDL-cholesterol and triglycerides were included. The median follow-up time for type 2 diabetes incidence was 7 years. Genetic variants were screened by restriction fragment length polymorphism or Illumina method.ResultsUCP3 gene variant rs3781907 was associated with increased serum total and LDL-cholesterol levels, at baseline and during the follow-up period. The same variant was associated with a higher risk of type 2 diabetes. Variants rs1726745, rs11235972 and rs1800849 in the UCP3 gene associated with serum total and LDL-cholesterol at baseline. Haploblock including variants rs659366, rs653529, rs15763, and rs1726745 was associated with measures of abdominal obesity at baseline and in the longitudinal analysis. The haplotype comprising alleles rs659366-G, rs653529-A, rs15763-G and rs1726745-A was associated with higher waist-to-hip ratio, and haplotype comprising alleles rs3781907-G, rs11235972-A, and rs1800849-T was associated with increased serum total and LDL-cholesterol concentrations.ConclusionGenetic variation in the UCP2-UCP3 gene cluster may act as a modifier increasing serum lipid levels and indices of abdominal obesity, and may thereby also contribute to the metabolic aberrations observed in obesity and type 2 diabetes.

Variations in the Ghrelin Receptor Gene Associate with Obesity and Glucose Metabolism in Individuals with Impaired Glucose Tolerance

Background Ghrelin may influence the development of obesity through its role in the control of energy balance, food intake, and regulation of body weight. The effects of ghrelin are mediated via the growth hormone secretagogue receptor (GHSR). Methodology/Principal Findings We genotyped 7 single nucleotide polymorphisms (SNPs) in the GHSR gene and assessed the association between those SNPs and obesity and type 2 diabetes-related phenotypes from 507 middle-aged overweight persons with impaired glucose tolerance participating in the Finnish Diabetes Prevention Study (DPS). Additionally, we performed in silico screening of the 5′-regulatory region of GHSR and evaluated SNPs disrupting putative transcription factor (TF) binding sites in vitro with gelshift assays to determine differences in protein binding between different alleles of SNPs. Rs9819506 in the promoter region of GHSR was associated with body weight (p = 0.036); persons with rs9819506-AA genotype having the lowest body weight. Individuals with rs490683-CC genotype displayed highest weight loss in the whole study population (p = 0.032). The false discovery rate for these results was <10%. Rs490683 and rs509035 were associated with several measures of glucose and insulin metabolism during the follow-up. Rs490683 may be a functional SNP, since gelshift experiments showed differential protein binding between the alleles, with higher binding to the G-allele. Rs490683-C may disrupt a putative binding site for the TF nuclear factor 1 (NF-1), thus rs4906863-GG genotype where the NF-1 site is intact may lead to a higher GHSR gene expression. Conclusion/Significance Polymorphisms in the GHSR promoter may modify changes in body weight during long-term lifestyle intervention and affect ghrelin receptor signalling through modulation of GHSR gene expression.