The interleukin-6 promoter polymorphism is associated with elevated leukocyte, lymphocyte, and monocyte counts and reduced physical fitness in young healthy smokers.

Smoking and interleukin-6 are important factors in driving inflammation. This study assessed the relationship between smoking, interleukin-6 genotype, physical fitness, and peripheral blood count in healthy young men. For this interleukin-6 promoter polymorphism -174 genotype-phenotype association study 1,929 healthy German male aviators recruited at the central German Air Force Institute of Aviation Medicine were stratified by smoking habits. Cardiovascular fitness was expressed as maximal physical working capacity (PWCmax) in watts per kilogram body weight as assessed by maximal exercise testing by cycle ergometry up to physical exhaustion. Smokers had higher leukocyte and lymphocyte counts than nonsmokers and lower PWCmax. In the overall study population the C allele of the interleukin-6 polymorphism was weakly associated with elevated leukocytes and lymphocytes; in nonsmokers the interleukin-6 polymorphism was not associated with altered phenotypes, but in smokers the interleukin-6 C allele was associated with higher leukocytes, lymphocytes, and monocytes and with lower PWCmax. Smoking is thus associated with elevated leukocytes and lymphocytes and with reduced physical fitness. Gene carriers with the interleukin-6 C allele may suffer particularly from cigarette smoking.

Relation between the angiotensinogen (AGT) M235T gene polymorphism and blood pressure in a large, homogeneous study population.

The aim of this study was to assess the association of the angiotensinogen M235T polymorphism with arterial blood pressure (BP) at rest and under physical stress in a homogeneous large-scale study population. In all, 1903 men who passed routine medical examination for military flying duty were recruited. BP and heart rate were measured at rest, during, and after bicycle ergometry. Genotyping for the AGT M235T polymorphism was carried out by PCR and RFLP technique. The AGT T235 allele was associated with a significantly higher diastolic BP (n=1903; MM 81+/-8, MT 83+/-7, TT 83+/-8; P=0.003). Pulse pressure (PP) at rest differed significantly between AGT genotypes (n=1903; MM 51+/-10 mmHg, MT 49+/-10 mmHg, TT 49+/-10 mmHg; P=0.001). During physical activity, BP values showed no significant difference between genotypes. In healthy young men, the AGT T235 allele is significantly associated with elevated diastolic BP but also reduced PP at rest. During physical activity, the AGT polymorphism had no impact on blood pressure, indicating the existence of other counteracting mechanisms, which might balance the influence of this gene.

Relation of body mass index, physical fitness, and the cardiovascular risk profile in 3127 young normal weight men with an apparently optimal lifestyle.

Obesity is a well-accepted cardiovascular risk factor associated with hypertension and hyperlipidaemia. A body mass index (BMI) within the range of 18.5-25 kg/m(2) is considered normal. To prevent cardiovascular diseases regular physical activity and abstinence from smoking are strongly recommended. Since it is not evident that a lower optimal threshold exists concerning cardiovascular risk factors if other lifestyle conditions are apparently optimised, we studied the relation between BMI and vascular risk factors in 3127 hyperhealthy Caucasian males. They were aged between 18 and 23 y, were nonsmokers, without regular alcohol intake, and had at least 3 h of sports activity per week. Their BMI was below 25 kg/m(2). Low BMI revealed to be significantly associated with high physical fitness, low blood pressure, and low serum lipids. The lower the BMI was, the more favourable these parameters were. Thus, the threshold for an optimal BMI concerning cardiovascular risk factors might be far below 25 kg/m(2) even if other lifestyle conditions are apparently optimal.

The vitamin D receptor gene variant and physical activity predicts fasting glucose levels in healthy young men.

AIMS: Vitamin D can influence lipolysis and insulin secretion. A common genetic polymorphism of the vitamin D receptor (VDR), which has been found to be associated with bone mineral density, has been reported to be also associated with Type 2 diabetes mellitus (DM). To test the influence of the VDR polymorphism on fasting glucose in healthy young men before the onset of Type 2 DM, we studied a homogeneous population of aircrew members. METHODS: A total of 1539 individuals were recruited during routine medical qualification for flying duty. Physical activity was assessed in all individuals and categorized into low physical activity ( 3 h per week). The BsmI VDR polymorphism was analysed by polymerase chain reaction. On the day of blood testing the individuals were fasting for at least 8 h overnight. Serum glucose was measured within 60 min after sampling venous blood. RESULTS: In young males with low physical activity (n = 752) gene carriers with the VDR genotype BB (n = 137) have significantly (P < 0.001) higher levels of fasting glucose (5.61 +/- 0.49 mmol/l) than gene carriers with the genotype Bb (n = 370; 5.44 +/- 0.44 mmol/l) or bb (n = 245; 5.38 +/- 0.44 mmol/l). Of BB gene carriers, 47% had fasting glucose levels > 5.55 mmol/l compared with 36% of Bb gene carriers and 34% of bb gene carriers (P = 0.018). This effect is absent in gene carriers with high physical activity (n = 787). CONCLUSIONS: The VDR genotype is associated with altered fasting glucose levels in young men with low physical activity. If this association is confirmed in other populations it might be worthwhile studying the particular benefits of an exercise programme in dependents of the VDR genotype.