Prednisolone Versus Colchicine for Acute Gout in Primary Care: statistical analysis plan for the pragmatic, multicenter, randomized, and double-blinded COPAGO non-inferiority trial.

BACKGROUND: To date, colchicine and prednisolone are two effective therapies for the treatment of acute gout but have never been compared directly in a randomized clinical trial. In addition, in previous trials of treating acute gout patients with concomitant comorbidities were often excluded due to contraindications to naproxen. STUDY DESIGN: This pragmatic, prospective, double-blind, double-dummy, parallel-group, randomized, non-inferiority trial compares prednisolone with colchicine in terms of non-inferiority in patients with acute gout. Patients presenting to their general practitioner with acute gout can be included if the gout attack has occurred within the last 2 days. A total of 60 practices in the vicinity of three university medical centers (Greifswald, Göttingen, and Würzburg) participate in the study. The intervention group receives 30 mg prednisolone for 5 days, while the group of standard care receives low-dose colchicine (day 1: 1.5 mg; days 2-5: 1 mg). The first dose of treatment is provided at day 0 when patients present to the general practitioner due to an acute gout attack. From day 0 to day 6, patients will be asked to complete a study diary on daily basis regarding pain quantification. For safety reasons, potential side effects and the course of systolic blood pressure are also assessed. STATISTICAL ANALYSIS PLAN: N = 314 patients have to be recruited to compensate for 10% of dropout and to allow for showing non-inferiority of prednisolone compared to colchicine with a power of 90%. We use permuted block randomization with block sizes of 2, 4, and 6 to avoid imbalanced treatment arms in this multi-center study; patients are randomized in a 1:1 ratio. The absolute level of pain on day 3 (in the last 24 h) is the primary outcome and measured on a numerical rating scale (NRS: 0-10). Using a multiple linear regression model adjusted for age, sex, and pain at baseline, prednisolone is considered non-inferior if the effect estimate including the confidence intervals is lower than a margin of 1 unit on the NRS. Average response to treatment, joint swelling and tenderness, physical function of the joint, and patients' global assessment of treatment success are secondary outcomes. DISCUSSION: The trial will provide evidence from a direct comparison of colchicine and prednisolone regarding their efficacy of pain reduction in acute gout patients of primary care and to indicate possible safety signals. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05698680 first posted on January 26, 2023 (retrospectively registered).

Distribution and determinants of glycosylated hemoglobin in adolescents - Results from a nationwide population-based survey in Germany.

The role of glycosylated hemoglobin (HbA1c) in youth is largely unclear. The aims of this study are to investigate the distribution and potential determinants of HbA1c among a population-based sample of adolescents. The German Health Interview and Examination Survey for Children and Adolescents (KiGGS) Wave 2 includes a nationwide representative sample of 0-17-year-old participants. For this evaluation, data from a randomly selected subgroup aged 14-17 years and without diagnosed diabetes was included (n = 857). Percentile-based HbA1c values (measured at laboratory in whole blood samples by high performance liquid chromatography) were calculated to examine HbA1c distribution. Multivariable linear regression analyses were performed to investigate factors (age, sex, parental socioeconomic status, body mass index (BMI), birth weight, smoking, alcohol consumption, healthy food diversity, sport activity, oral contraceptive use) associated with HbA1c. The mean HbA1c level was 5.2% (minimum: 3.9%, P10: 4.8%, P50: 5.1%, P90: 5.5%, maximum: 6.7%). Overall, 2.8% of adolescents had an HbA1c value in the prediabetic range (5.7-6.4%) and 0.1% had an undiagnosed diabetes (≥6.5%). Multivariable regression analysis showed an inverse association of age with HbA1c (17 vs. 14 years: ß: -1.18; 95% CI -2.05, -0.31). Higher HbA1c values were observed for higher BMI-standard deviation scores (SDS) (ß: 0.24; 95% CI -0.04, 0.52) and smoking (ß: 0.73; 95% CI -0.12, 1.57), but these tendencies were non-significant. In sex-stratified analysis, smoking and birth weight were significantly associated with HbA1c in boys. Among adolescents without diagnosed diabetes in Germany, HbA1c values ranged from 3.9% to 6.7%. To ensure health in adulthood, the influence of determinants on HbA1c levels in younger age should be further investigated.

Prednisolone Versus Colchicine for Acute Gout in Primary Care (COPAGO): protocol for a two-arm multicentre, pragmatic, prospective, randomized, double-blind, controlled clinical trial of prednisolone and colchicine for non-inferiority with a parallel group design.

BACKGROUND: Gout is the most common form of rheumatic disease in which monosodium urate crystals are deposited in the joints followed by acute inflammatory reactions. There are various approved drugs that can be prescribed for pain relief during an acute gout attack. However, to date, no direct comparison of efficacy of colchicine and prednisolone for the treatment of acute gout attacks has been investigated. Furthermore, the majority of previous research studies were not only conducted in tertiary centres but also excluded patients with common comorbidities due to contraindications to naproxen. METHODS: This pragmatic, prospective, double-blind, double-dummy, parallel-group, randomized, non-inferiority trial investigates whether prednisolone (intervention) is non-inferior to treatment with colchicine (active control) in patients with acute gout. Adult patients presenting with acute gout to their general practitioners in 60 practices across 3 university sites (Greifswald, Göttingen, and Würzburg) are eligible to participate in the study. Participants in the intervention group receive 30 mg prednisolone for 5 days. Those in the control group receive low-dose colchicine (day 1: 1.5 mg; days 2-5: 1 mg). The primary outcome is the absolute level of the most severe pain on day 3 (in the last 24 h) measured with an 11-item numerical rating scale. Day 0 is the day patients take their study medication for the first time. They are then asked to fill out a study diary the same time each day for pain quantification. Pain scores are used for comparison between the two medications. Secondary outcomes are average response to treatment, swelling, tenderness and physical function of the joint, patients' global assessment of treatment success, use of additional pain medication and non-pharmacological pain therapies. For safety reasons, potential side effects and course of systolic blood pressure are assessed. DISCUSSION: This trial will provide evidence on the effectiveness of pain reduction and side effects of colchicine and prednisolone in acute gout in primary care. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05698680 first posted on January 26, 2023 (retrospectively registered). URL of trial registry record: https://clinicaltrials.gov/study/NCT05698680.

Association of Lumbar MRI Findings with Current and Future Back Pain in a Population-based Cohort Study.

STUDY DESIGN: Population-based cohort study. OBJECTIVE: We examined associations between common lumbar degenerative changes observed on magnetic resonance imaging (MRI) and present or future low back pain (LBP). SUMMARY OF BACKGROUND DATA: The association between lumbar MRI degenerative findings and LBP is unclear. Longitudinal studies are sparse. METHODS: Participants (n = 3369) from a population-based cohort study were imaged at study entry, with LBP status measured at baseline and 6-year follow-up. MRI scans were reported on for the presence of a range of MRI findings. LBP status was measured on a 0 to 10 scale. Regression models were used to estimate the cross-sectional and longitudinal associations between individual and multiple MRI findings and LBP severity. Separate longitudinal analyses were conducted for participants with and without baseline pain. RESULTS: MRI findings were present in persons with and without back pain at baseline. Higher proportions were found in older age groups. 76.4% of participants had a least one MRI finding and 8.3% had five or more different MRI findings. Cross-sectionally, most MRI findings were slightly more common in those with LBP and pain severity was slightly higher in those with MRI findings (ranging from 0.06 for high intensity zone to 0.83 for spondylolisthesis). In the longitudinal analyses, we found most MRI findings were not associated with future LBP-severity regardless of the presence or absence of baseline pain. Compared to zero MRI findings, having multiple MRI findings (five or more) was associated with mildly greater pain-severity at baseline (0.84; 0.50-1.17) and greater increase in pain-severity over 6 years in those pain free at baseline (1.21; 0.04-2.37), but not in those with baseline pain (-0.30; -0.99 to 0.38). CONCLUSION: Our study shows that the MRI degenerative findings we examined, individually or in combination, do not have clinically important associations with LBP, with almost all effects less than one unit on a 0 to 10 pain scale.Level of Evidence: 3.

Sex-specific impact of major depressive disorder on 12-year change in glycaemic status: Results from a nationwide cohort study of adults without diabetes in Germany.

AIMS: There is evidence for an increased type 2 diabetes (T2D) risk associated with depression, but its role for diabetes prevention remains unclear. This study aimed to add insight by investigating the impact of major depressive disorder (MDD) on prospective glycaemic changes. METHODS: The study was based on a cohort of n = 1,766 adults without diabetes (776 men, 990 women; 18-65 years of age) who participated in the mental health supplement of the German National Health Interview and Examination Survey (GNHIES98-MHS, 1997-1999) and in a follow-up survey (DEGS1, 2008-2011). Glycaemic status was defined as normoglycaemia [HbA1c < 39 mmol/mol (<5.7%)], prediabetes [39 ≤ HbA1c < 48 mmol/mol (5.7-6.4%)] and diabetes [HbA1c ≥ 48 mmol/mol (≥ 6.5%), diagnosed diabetes, or antidiabetic medication], and glycaemic changes categorized as 'remission', 'stability' and 'progression'. Baseline MDD was assessed via a modified German version of the WHO Composite International Diagnostic Interview. Multivariable logistic regressions were applied to analyse the association of MDD with glycaemic changes and incident T2D, adjusting for socio-demographics, lifestyle conditions, chronic diseases, antidepressant use and mental health care. RESULTS: MDD prevalence was 21.4% for women and 8.9% for men. Among women, MDD was associated with a lower chance for remission (RRR 0.43; 95% CI 0.23, 0.82). Among men, MDD was not significantly related to glycaemic changes. MDD had no significant effect on incident T2D (men: OR 1.58; 0.55, 4.52; women: OR 0.76; 0.37, 1.58). CONCLUSIONS: Findings of the current study highlight the role of depression in T2D prevention, particularly among women.

Predicting Physician Consultations for Low Back Pain Using Claims Data and Population-Based Cohort Data-An Interpretable Machine Learning Approach.

(1) Background: Predicting chronic low back pain (LBP) is of clinical and economic interest as LBP leads to disabilities and health service utilization. This study aims to build a competitive and interpretable prediction model; (2) Methods: We used clinical and claims data of 3837 participants of a population-based cohort study to predict future LBP consultations (ICD-10: M40.XX-M54.XX). Best subset selection (BSS) was applied in repeated random samples of training data (75% of data); scoring rules were used to identify the best subset of predictors. The rediction accuracy of BSS was compared to randomforest and support vector machines (SVM) in the validation data (25% of data); (3) Results: The best subset comprised 16 out of 32 predictors. Previous occurrence of LBP increased the odds for future LBP consultations (odds ratio (OR) 6.91 [5.05; 9.45]), while concomitant diseases reduced the odds (1 vs. 0, OR: 0.74 [0.57; 0.98], >1 vs. 0: 0.37 [0.21; 0.67]). The area-under-curve (AUC) of BSS was acceptable (0.78 [0.74; 0.82]) and comparable with SVM (0.78 [0.74; 0.82]) and randomforest (0.79 [0.75; 0.83]); (4) Conclusions: Regarding prediction accuracy, BSS has been considered competitive with established machine-learning approaches. Nonetheless, considerable misclassification is inherent and further refinements are required to improve predictions.

Age, maturation and serum lipid parameters: findings from the German Health Survey for Children and Adolescents.

BACKGROUND: Recommendations on preventive lipid screening among children and adolescents remain controversial. The aim of the study was to assess age and puberty-related changes in serum lipids, including total cholesterol (TC), and high-density (HDL-C) and non-high-density lipoprotein cholesterol (Non-HDL-C). METHODS: Using cross-sectional data from the National Health Interview and Examination Survey for Children and Adolescents in Germany (KiGGS 2003-2006; N = 13,676; 1-17 years), changes in distributions of serum lipids were visualized according to sex, age and maturation. Youth aged 10-17 years were classified as prepubescent, early/mid-puberty, and mature/advanced puberty. Multiple linear regressions were used to quantify the impact of pubertal stage on serum lipid levels, adjusted for potential confounding factors. RESULTS: Among children 1-9 years mean serum lipid measures increased with age, with higher mean TC and Non-HDL-C among girls than boys. Among children 10-17 years, advanced pubertal stage was independently related to lower lipid measures. Adjusted mean TC, HDL-C and Non-HDL-C was 19.4, 5.9 and 13.6 mg/dL lower among mature/advanced puberty compared to prepubescent boys and 11.0, 4.0 and 7.0 mg/dL lower in mature/advanced puberty compared to prepubescent girls. CONCLUSIONS: Lipid concentrations undergo considerable and sex-specific changes during physical growth and sexual maturation and significantly differ between pubertal stages. Screening recommendations need to consider the fluctuations of serum lipids during growth and sexual maturation.

Physical health-related quality of life in relation to metabolic health and obesity among men and women in Germany.

BACKGROUND: This study examined sex-specific differences in physical health-related quality of life (HRQoL) across subgroups of metabolic health and obesity. We specifically asked whether (1) obesity is related to lower HRQoL independent of metabolic health status and potential confounders, and (2) whether associations are similar in men and women. METHODS: We used cross-sectional data from the German Health Interview and Examination Survey 2008-11. Physical HRQoL was measured using the Short Form-36 version 2 physical component summary (PCS) score. Based on harmonized ATPIII criteria for the definition of the metabolic health and a body mass index ≥ 30 kg/m2 to define obesity, individuals were classified as metabolically healthy non-obese (MHNO), metabolically unhealthy non-obese (MUNO), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO). Sex-specific analyses including multivariable linear regression analyses were based on PCS as the dependent variable, metabolic health and obesity category as the independent variable with three categories and MHNO as the reference, and age, education, lifestyle and comorbidities as confounders. RESULTS: This study included 6860 participants (3298 men, 3562 women). Compared to MHNO, all other metabolic health and obesity categories had significantly lower PCS in both sexes. As reflected by the beta coefficients [95% confidence interval] from bivariable linear regression models, a significant inverse association with PCS was strongest for MUO (men: -7.0 [-8.2; -5.8]; women: -9.0 [-10.2; -7.9]), intermediate for MUNO (men: -4.2 [-5.3; -3.1]; women: -5.6 [-6.8; -4.4]) and least pronounced for MHO (men: -2.2 [-3.6; -0.8]; women -3.9 [-5.4; -2.5]). Differences in relation to MHNO remained statistically significant for all groups after adjusting for confounders, but decreased in particular for MUNO (men:-1.3 [-2.3; -0.3]; women: -1.5 [-2.7; -0.3]. CONCLUSIONS: Obesity was significantly related to lower physical HRQoL, independent of metabolic health status. Potential confounders including age, educational status, health-related behaviors, and comorbidities explained parts of the inverse relationship. Associations were evident in both sexes and consistently more pronounced among women than men.

[Changes in the prevalence of statin use in Germany - findings from national health interview and examination surveys 1997-1999 and 2008-2011]. / Zeitliche Entwicklung der Anwendungsprävalenz von Statinen in Deutschland ­ Ergebnisse der nationalen Interview- und Untersuchungssurveys 1997-1999 und 2008-2011.

BACKGROUND: Evidence-based guideline recommendations on lipid lowering drug treatment, in particular statin treatment, play an essential role in the management of dyslipidemias and in the prevention of cardiovascular disease events. In Germany, statutory health insurance data provide information on time trends in the prescription of lipid lowering drugs. However, population-based data regarding changes in user prevalence according to socio-demographic and health-related characteristics are lacking. Based on data from national health interview and examination surveys for adults in Germany 1997-1999 (GNHIES98) and 2008-2010 (DEGS1), the present analysis aims to close this information gap with a particular focus on the use of statins. METHODS: The study population consisted of 7,099 participants (GNHIES98) and 7,091 participants (DEGS1) aged 18 to 79 years at the time of the respective surveys. Primary data on medication use within 7 days prior to the survey were collected using standardized medication interviews and brown-bag drug review. Unique product identifiers on original drug containers were scanned and coded according to the latest version of the Anatomical Therapeutic Chemical (ATC) classification system. Medical history was obtained in computer-assisted personal interviews. A history of stroke or coronary heart disease (CHD) was assessed among persons aged 40 to 79 years only, and previous stroke or CHD were defined as cardiovascular disease. Obesity was defined as a body mass index (BMI) of ≥ 30kg/m2) based on calculation from standardized measures of body weight and height. Information on socio-demographic variables and type of health insurance was collected using standardized self-administered questionnaires. In cross-sectional descriptive analyses we calculated the prevalence of statin use (ATC codes: C10AA, C10BA, C10BX) by survey as well as the changes between surveys stratified according to relevant preexisting diseases and other co-variables. The association between survey period and statin use was analyzed in multivariable binary logistic regression models among persons aged 40 to 79 years. All results were weighted and standardized for the population of 2010. RESULTS: Between the two survey periods 1997-1999 and 2008-2011, the prevalence of statin use increased from 3.2 % to 8.8 %. The increase was most pronounced for the age group 65 to 79 years (7.2 % vs. 26.9 %) and among persons with relevant preexisting conditions, such as CHD (19.1 % vs. 54.9 %), stroke (17.1 % vs. 50.1 %), diabetes mellitus (10.5 % vs. 33.2 %), and dyslipidemia (12.6 % vs. 27.8 %). Among persons aged 40 to 79 years, the prevalence of statin use significantly increased between the two surveys, independent of co-variables (Odds Ratio: 3.70; 95 % confidence interval [CI]: 2.92 to 4.70). This applied to persons with cardiovascular disease (5.17; 3.50 to 7.64) and without cardiovascular disease (2.76; 2.07 to 3.67). CONCLUSION: The increase in the prevalence of statin use in Germany between the two national health surveys (1997-1999 and 2008-2011) reflects the implementation of current guideline recommendations without evidence for inequalities according to gender, education, type of health insurance or region of residence. These population-based data add to information on statin prescription obtained from statutory health insurance data. Limitations of survey-based information derive from potential misclassification and selection bias as well as large time gaps between the survey periods. Further studies are needed to examine why the observed prevalence of statin use among persons with cardiovascular morbidity lags behind current guideline recommendations for secondary cardiovascular prevention.

Time Trends in Cardiometabolic Risk Factors in Adults.

BACKGROUND: Data from three representative health examination surveys in Germany were analyzed to examine secular trends in the prevalence and magnitude of cardiometabolic risk factors. METHODS: The target variables were the following cardiometabolic risk factors: lack of exercise, smoking, obesity, systolic blood pressure, total cholesterol, serum glucose, self-reported high blood pressure, hyperlipidemia, and diabetes, and the use of antihypertensive, cholesterol-lowering, and antidiabetic drugs. 9347 data sets from men and 10 068 from women were analyzed. The calculated means and prevalences were standardized to the age structure of the German population as of 31 December 2010 and compared across the three time periods of the surveys: 1990-1992, 1997-1999, and 2008-11. RESULTS: Over the entire period of observation (1990-2011), the mean systolic blood pressure fell from 137 to 128 mmHg in men and from 132 to 120 mmHg in women; the mean serum glucose concentration fell from 5.6 to 5.3 mmol/L in men and from 5.4 to 5.0 mmol/l in women; and the mean total cholesterol level fell from 6.2 to 5.3 mmol/L in both sexes. In men, smoking and lack of exercise became less common. On the other hand, the prevalence of use of antidiabetic, cholesterol-lowering, and antihypertensive drugs rose over the same time period, as did that of self-reported diabetes. The first of the three surveys (1990-1992) revealed differences between persons residing in the former East and West Germany in most of the health variables studied; these differences became less marked over time, up to the last survey in 2008-2011. CONCLUSION: The cardiometabolic risk profile of the German adult population as a whole improved over a period of 20 years. Further in-depth analyses are now planned.

Metabolic Health in Relation to Body Size: Changes in Prevalence over Time between 1997-99 and 2008-11 in Germany.

OBJECTIVE: The study examined potential changes in the proportion of metabolic health according to body size categories over time and across strata of sex and age, varying definitions of metabolic health. METHODS: We analysed data from national health interview and examination surveys 1997-99 and 2008-11 for adults aged 18-79 years (GNHIES98: N = 6,565; DEGS1: 6,860). Metabolic health as defined by ATPIII criteria was examined across body mass index categories. The Plourde and Karelis criteria were applied in relation to abdominal obesity. RESULTS: Proportions of adults with metabolic health by body size categories were largely stable over time, except for an increasing proportion of metabolically healthy persons with pre-obesity and metabolically healthy women without abdominal obesity. In both surveys proportions of adults meeting ATPIII criteria ranged from approximately 30% among men and women with obesity, to about two thirds of those with pre-obesity to about 93% among those with normal weight. According to Plourde and Karelis criteria proportions ranged from almost 30% among men and women without abdominal obesity to less than 10% among those with abdominal obesity. Proportions were consistently higher among younger than older age groups and less consistently higher among women than men. CONCLUSIONS: Proportions of adults with metabolic health by body size categories were largely stable over time, except for an increasing proportion of metabolically healthy women without abdominal obesity. There is no evidence that metabolic health among adults with obesity increased in Germany over a period of ten years.

Changes in mean serum lipids among adults in Germany: results from National Health Surveys 1997-99 and 2008-11.

BACKGROUND: Monitoring of serum lipid concentrations at the population level is an important public health tool to describe progress in cardiovascular disease risk control and prevention. Using data from two nationally representative health surveys of adults 18-79 years, this study identified changes in mean serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) in relation to changes in potential determinants of serum lipids between 1997-99 and 2008-11 in Germany. METHODS: Sex-specific multivariable linear regression analyses were performed with serum lipids as dependent variables and survey wave as independent variable and adjusted for the following covariables: age, fasting duration, educational status, lifestyle, and use of medication. RESULTS: Mean TC declined between the two survey periods by 13 % (5.97 mmol/l vs. 5.19 mmol/l) among men and by 12 % (6.03 mmol/l vs. 5.30 mmol/l) among women. Geometric mean TG decreased by 14 % (1.66 mmol/l vs. 1.42 mmol/l) among men and by 8 % (1.20 mmol/l vs. 1.10 mmol/l) among women. Mean HDL-C remained unchanged among men (1.29 mmol/l vs. 1.27 mmol/l), but decreased by 5 % among women (1.66 mmol/l vs. 1.58 mmol/l). Sports activity and coffee consumption increased, while smoking and high alcohol consumption decreased only in men. Processed food consumption increased and wholegrain bread consumption decreased in both sexes, and obesity increased among men. The use of lipid-lowering medication, in particular statins nearly doubled over time in both sexes. Among women, hormonal contraceptive use increased and postmenopausal hormone therapy halved over time. The changes in lipid levels between surveys remained significant after adjusting for covariables. CONCLUSION: Serum TC and TG considerably declined over one decade in Germany, which can be partly explained by increased use of lipid-lowering medication and improved lifestyle among men. The decline in serum lipids among women, however, remains unexplained.

Modifiable cardiovascular risk factors in adults aged 40-79 years in Germany with and without prior coronary heart disease or stroke.

BACKGROUND: Control of modifiable cardiovascular disease (CVD) risk factors has substantially reduced CVD mortality, but risk factor levels in populations may change and need continuous monitoring. This study aims to provide current estimates of the prevalence of these risk factors in Germany according to sex and history of coronary heart disease (CHD) or stroke. METHODS: The analyses were based on data from the German Health Interview and Examination Survey for Adults (DEGS1; age 40-79 years, n = 5101), which is a cross-sectional population-based examination survey. CVD risk factors were defined according to recommendations in the European Guidelines on Cardiovascular Disease Prevention in Clinical Practice 2012. RESULTS: The mean age was 57 years and 52% were female; 493 participants had prior CHD and 163 participants a prior stroke. The overall prevalence of behavioural risk factors ranged from 17.9% for high risk alcohol consumption to 90% for low vegetable intake. Blood pressure ≥ 140/90 mmHg was found in 21% and 69% had total cholesterol ≥ 5.0 mmol/l. Only 16% met the targets for five behavioural factors combined (smoking, physical activity, fruit intake, alcohol intake and obesity), 13% of those with and 16% of those without CHD or stroke. The prevalences of most behavioural risk factors were higher among men compared to women. CONCLUSIONS: There is a high prevention potential from modifiable cardiovascular risk factors in the general population aged 40-79 years in Germany and among those with prior CHD or stroke. Risk factors are often co-occurring, are interrelated and require combined educational, behavioral, medical and policy approaches.

Associations of dietary indices with biomarkers of dietary exposure and cardiovascular status among adolescents in Germany.

BACKGROUND: Adolescence is an important life stage for the development of dietary preferences and health behaviour. Longitudinal studies indicated that cardiovascular status in adolescence predicts cardiovascular risk marker values in adulthood. Several diet quality indices for adolescents have been developed in the past, but literature concerning associations between indices and biomarkers of dietary exposure and cardiovascular status is rather sparse. Hence, the aim of this study was to analyse associations of dietary indices with biomarkers of dietary exposure and cardiovascular status. METHODS: For the present analysis, data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS 2003-2006) were used. The analysis included 5,198 adolescents, aged 12 to 17 years. The Healthy Food Diversity Index (HFD), the Healthy Nutrition Score for Kids and Youth (HuSKY), the Indicator Food Index (IFI) and a simple fruit/vegetable intake index were derived from food frequency questionnaire information to indicate a healthy diet. Adjusted mean values for homocysteine, uric acid, CRP, total cholesterol, HDL-C, ferritin, HbA1c, folate, vitamin B12 and BMI were calculated using complex-samples general linear models for quintiles of the different indices. Furthermore, the agreement in ranking between the different indices was calculated by weighted kappa. All statistical analyses were conducted for boys and girls separately, and were adjusted for potential confounders. RESULTS: Folate was positively associated with the HFD, the HuSKY, and fruit/vegetable intake for both boys and girls and with IFI for boys. Among girls, positive associations were seen between vitamin B12 and the IFI and between diastolic blood pressure and the IFI as well as fruit/vegetable intake. A negative association was found between homocysteine and the HFD, the HuSKY, and the IFI for both boys and girls and with fruit/vegetable intake for boys. Among boys, uric acid and HbA1c were negatively and prevalence of obesity positively associated with the IFI. CONCLUSIONS: Overall, the indices, even the simpler ones, seem to have a similar general capability in predicting biomarkers of dietary exposure. To predict risk of cardiovascular disease dietary indices may have to be more specific.

Relative validation of the KiGGS Food Frequency Questionnaire among adolescents in Germany.

BACKGROUND: The aim of this study was to determine the relative validity of the self-administered Food Frequency Questionnaire (FFQ) "What do you eat?", which was used in the German National Health Interview and Examination Survey for Children and Adolescents (KiGGS 2003-2006). METHODS: The validation was conducted in the EsKiMo Nutrition Module, a subsample of KiGGS. The study population included 1,213 adolescents aged between 12 and 17. A modified diet history interview DISHES (Dietary Interview Software for Health Examination Studies) was used as the reference method. In order to compare the food groups, the data assessed with both instruments were aggregated to 40 similar food groups. The statistical analysis included calculating and comparing Spearman's correlation coefficients, calculating the mean difference between both methods, and ranking participants (quartiles) according to food group consumption, including weighted kappa coefficients. Correlations were also evaluated for relative body weight and socioeconomic status subgroups. RESULTS: In the total study population the Spearman correlation coefficients ranged from 0.22 for pasta/rice to 0.69 for margarine; most values were 0.50 and higher. The mean difference ranged between 1.4% for milk and 100.3% for pasta/rice. The 2.5 percentiles and 97.5 percentiles indicated a wide range of differences. Classifications in the same and adjacent quartile varied between 70.1% for pasta/rice and 90.8% for coffee. For most groups, Cohen's weighted kappa showed values between 0.21 and 0.60. Only for white bread and pasta/rice were values less than 0.20. Most of the 40 food groups showed acceptable to good correlations in all investigated subgroups concerning age, sex, body weight and socio-economic status. CONCLUSIONS: The KiGGS FFQ showed fair to moderate ranking validity except for pasta/rice and white bread. However, the ability to assess absolute intakes is limited. The correlation coefficients for most food items were similar for normal weight and overweight as well as for different socio-economic status groups. Overall, the results of the relative validity were comparable to FFQs from the current literature.