Regional differences in the prevalence of left ventricular hypertrophy within Germany

Geographic origin as a determinant of left ventricular mass and diastolic function – the Cardiovascular Risk in Young Finns Study

Aims: Eastern Finns have higher risk of coronary heart disease (CHD) and carotid intima-media thickness than western Finns although current differences in CHD risk factors are minimal. Left ventricular (LV) mass and diastolic function predict future cardiovascular events but their east–west differences are unknown. We examined the association of eastern/western baseline origin with LV mass and diastolic function. Methods : The study population included 2045 subjects of the Cardiovascular Risk in Young Finns Study with data from the baseline survey (1980) and the latest follow-up (2011) when echocardiography was performed at the age of 34–49 years. Results: Subjects with eastern baseline origin had in 2011 higher LV mass (139±1.0 vs. 135±1.0 g, p=0.006) and E/e′-ratio indicating weaker LV diastolic function (4.86±0.03 vs. 4.74±0.03, p=0.02) than western subjects. Results were independent of age, sex, area of examination and CHD risk factors such as blood pressure and BMI (LV mass indexed with height: p<0.0001; E/e′-ratio: p=0.01). LV end-diastolic volume was higher among subjects with eastern baseline origin (135±0.9 vs. 131±0.9 ml, p=0.0011) but left atrial end-systolic volume, also indicating LV diastolic function, was not different between eastern and western subjects (43.4±0.5 vs. 44.0±0.5 ml, p=0.45). Most of the subjects were well within the normal limits of these echocardiographic measurements. Conclusions: In our healthy middle-aged population, geographic origin in eastern Finland associated with higher LV mass compared to western Finland. Higher E/e′-ratio suggests that subjects with eastern baseline origin might have higher prevalence of diastolic dysfunction in the future than western subjects.

Epidemiology in Germany-general development and personal experience

Did you ever hear about epidemiology in Germany? Starting from an epidemiological desert the discipline has grown remarkably, especially during the last 10-15 years: research institutes have been established, research funding has improved, multiple curriculae in Epidemiology and Public Health are offered. This increase has been quite steep, and now the epidemiological infrastructure is much better. Several medium-sized and even big population cohorts are ongoing, and the number and quality of publications from German epidemiologists has reached a respectable level. My own career in epidemiology started in the field of environmental health. After German reunification I concentrated for many years on environmental problems in East Germany and observed the health benefits after improvement of the situation. Later, I concentrated on population-based cohorts in newborns (GINI/LISA) and adults (KORA, German National Cohort), and on biobanking. This Essay describes the development in Germany after worldwar 2, illustrated by examples of research results and build-up of epidemiological infractructures worth mentioning.

Is hepatic steatosis associated with left ventricular mass index increase in the general population?

AIM

To investigate the association between hepatic steatosis and change in left ventricular mass index (LVMI) over five years, and examine whether systolic and diastolic blood pressures are mediators of the association between hepatic steatosis and LVMI using a general population sample.

METHODS

We analyzed data from the Study of Health in Pomerania. The study population comprised 1298 individuals aged 45 to 81 years. Hepatic steatosis was defined as the presence of a hyperechogenic pattern of the liver together with elevated serum alanine transferase levels. Left ventricular mass was determined echocardiographically and indexed to height^2.7. Path analyses were conducted to differentiate direct and indirect paths from hepatic steatosis to LVMI encompassing systolic and diastolic blood pressure as potential mediating variables.

RESULTS

Hepatic steatosis was a significant predictor for all measured echocardiographic characteristics at baseline. Path analyses revealed that the association of hepatic steatosis with LVMI change after five years was negligibly small (β = -0.12, s.e. = 0.21, P = 0.55). Systolic blood pressure at baseline was inversely associated with LVMI change (β = -0.09, s.e. = 0.03, P < 0.01), while no association between diastolic blood pressure at baseline and LVMI change was evident (β = 0.03, s.e. = 0.05, P = 0.56). The effect of the indirect path from hepatic steatosis to LVMI via systolic baseline blood pressure was small (β = -0.20, s.e. = 0.10, P = 0.07). No indirect effect was observed for the path via diastolic baseline blood pressure (β = 0.03, s.e. = 0.06, P = 0.60). Similar associations were observed in the subgroup of individuals not receiving beta-blockers, calcium channel blockers, or drugs acting on the renin-angiotensin system.

CONCLUSION

Baseline associations between hepatic steatosis and LVMI do not extend to associations with LVMI change after five years. More studies are needed to study the longitudinal effects of hepatic steatosis on LVMI.

[Study of Health in Pomerania (SHIP). Concept, design and selected results]

The Study of Health in Pomerania (SHIP) is a population-based project conducted in Northeast Germany. The main purpose is to assess prevalence and incidence of common risk factors, subclinical disorders and clinical diseases, and to investigate associations and interactions among them. The first SHIP cohort included 4,308 individuals at baseline (SHIP-0, response 68.8%) and 3,300 after 5 years (SHIP-1, response 83.6%). Currently, data are being collected for the 11-year follow-up (SHIP-2). In parallel, baseline examinations of a second, independent cohort (SHIP-TREND) are being conducted. The assessments range from interviews to laboratory analyses; somatometric and blood pressure measurements; dental, dermatological, cardio-metabolic and various ultrasound examinations; to more demanding methods such as cardiopulmonary exercise tests, sleep monitoring and whole-body magnetic resonance imaging. Analyses of baseline SHIP-0 data revealed valuable information on the health status of the West Pomeranian population, and generally confirmed the hypothesis of an accumulation of common risk factors and diseases in this region. The population-based character of the study and the profound information on potential exclusion criteria allow for analyses of population-representative reference values. The comprehensive data set offers various opportunities for association studies to gain new insight into the complex relations among risk factors, subclinical and clinical disease parameters. SHIP is an established population-based project conducted in Northeast Germany with a very comprehensive characterization of study subjects. After the data collection for SHIP-2 and SHIP-TREND is finished, a comprehensive data set will be available that describes complex interactions of health determinants.

A comparison of periodontal status in the two regional, population-based studies of SHIP and INVEST

OBJECTIVES

To compare the prevalence of periodontal disease between two randomly selected population-based studies (the Oral Infections and Vascular Disease Epidemiology Study (INVEST) and the Study of Health in Pomerania (SHIP)) and address relevant methodological issues.

METHODS

Comparison was restricted to 55- to 81-year olds. Attachment loss (AL), probing depth (PD) and tooth count were assessed in INVEST (full-mouth, six sites) and SHIP (half-mouth, four sites). Subjects were classified according to the CDC/AAP case definition. Recording protocols were standardized. Mixed linear or logistic models were used to compare INVEST with SHIP.

RESULTS

Mean half-mouth AL was lower in INVEST versus SHIP (INVEST: 2.9 mm versus SHIP: 4.0 mm, p < 0.05). Findings were similar across multiple periodontal disease definitions. After equalization of recording protocols and adjustment for periodontal risk factors, mean AL and PD were 1.2 and 0.3 mm lower in INVEST versus SHIP (p < 0.001). The odds for severe periodontitis (CDC/AAP) was 0.2-fold in INVEST versus SHIP (p < 0.001). Confounding effects of age, gender, race/ethnicity, education and use of interdental care devices were highest as indicated by change-in-estimate for study.

CONCLUSION

Implementation of the proposed method for comparison of epidemiological studies revealed that periodontitis was less prevalent in INVEST compared with SHIP, even after extensive risk-factor adjustment.

[Whole-body MRI in the study of health in Pomerania]

Population-based whole-body MRI examinations have been evaluated for the first time within the Study of Health in Pomerania (SHIP). This ongoing cohort study investigates associations of overweight (57.9% of the female and 74.1% of the male population) and obesity (25.1% and 26.0%, respectively) with cardiovascular and metabolic diseases in a population with decreased life expectancy compared to the total German average. Whole-body MRI offers the possibility to evaluate parameters, such as the amount of visceral and liver fat and can contribute to further conclusions on these common diseases.

Subclinical hyperthyroidism is not associated with progression of cardiac mass and development of left ventricular hypertrophy in middle-aged and older subjects: results from a 5-year follow-up

BACKGROUND

Decreased serum TSH levels are associated with increased cardiovascular mortality in elderly, and subclinical hyperthyroidism (SCH) was associated with left ventricular hypertrophy (LVH) as a predictor of cardiovascular mortality in some cross-sectional and case-control studies. The aim was to assess whether SCH independently impacts development of LVH over time.

METHODS

Of 3300 participants of the population-based Study of Health in Pomerania those with overt hyperthyroidism, hypothyroidism, possible thyroid disease or missing echocardiographic baseline data or follow-up were excluded, resulting in a study population of 1112 individuals (556 women) aged 45-81 years. Echocardiographic left ventricular mass divided by height(2·7) (LVMI(ht)), and LVH(ht) (LVMI(ht) > 44 g/m(2·7) in women and > 48 g/m(2·7) in men) was measured at baseline and after 5-year follow-up (median 5·00; range 4·92; 5·08). Comparison of subjects with (n = 107) and without (n = 1005) SCH were made by linear and logistic regression models adjusted for age, gender, smoking status, hypertension, and waist circumference.

RESULTS

At follow-up, LVMI(ht) did not differ between subjects with and without SCH (50·2 g/m(2·7), interquartile range (IQR) 41·2; 59·5 vs 47·8 g/m(2·7), IQR 39·3; 56·9; P = 0·29). LVH(ht) was present in 66 (61·7%) subjects with and 543 (54·0%) persons without SCH (P = 0·13). Analyses revealed no association between SCH and progression of LVMI(ht) (β = -0·18; 95%-confidence interval (CI) -2·34; -1·99; P = 0·873), and development of LVH(ht) (relative risk 0·86, 95%-CI 0·60; 1·26; P = 0·462), respectively.

CONCLUSIONS

In this population-based sample, SCH had no impact on progression of LVMI and development of LVH during 5-year follow-up in subjects aged 45 years or older.