Gender differences and age-specific associations between body mass index and other cardiovascular risk factors in CMV infected and uninfected people

Abstract

Body mass index (BMI) is a known risk factor for cardiovascular disease and cancer. It is also related to white blood count (WBC) and inflammation. The effects of age and gender on these associations have not been explored. Here we have examined the relationships between BMI and inflammatory parameters/cardiovascular risk factors including WBC/neutrophil count (NC), CRP and mean arterial blood pressure (MAP), in young (20-35 years) and older (60-85 years) healthy donors with respect to gender and CMV IgG serology. In young but not older people significant associations between BMI and WBC were observed, however, with opposite directions in the two genders. Only in CMV+ older women a positive trend was preserved. Across the population, there was no significant association between NC and MAP; however, among older men we saw a positive correlation between the two parameters. Linear regression confirmed that across the whole population, age group (young versus older) and also the interaction between gender and age group but not gender alone had significant effects on this association. When analysing CMV+ older people separately we established that both NC and its interaction with gender had a significant effect on MAP. This study reveals that the correlations between common inflammatory markers/cardiovascular risk factors depend on age, gender, and CMV status in a complex fashion. Our findings support the need to evaluate risk factors independently in men and women and to take into account CMV infection status. More focused studies will be required to shed light on these novel findings.

Keywords: Body mass index; CMV; Cardiovascular risk factors; Immunology; Infection; Inflammation.

Fig. 1

Correlations analysis between MBI and blood cell fraction counts was carried out in young and older donors, stratified by their CMV status. Empty black circles and black dotted black lines indicate WBC, filled black circles and solid black lines indicate neutrophils, grey diamonds and grey dotted grey lines indicate lymphocytes, filled grey triangles and grey solid lines indicate monocytes. Note that significant correlations are observed in young CMV+ women (R = 0.580/p = 0.015* and R = 0.538/p = 0.026*, for WBC and NC respectively).

Fig. 2

Linear correlations analysis between CRP (log transformed) and WBC (empty circles) or NC (full circles) in older people. Lines correspond to Pearson correlation and relative values are reported in a summary table.

Fig. 3

Correlations analysis between MAP and blood cell fractions counts, in young and older donors, split by CMV status. Empty black circles and black dotted black lines indicate WBC, filled black circles and solid black lines indicate neutrophils, grey diamonds and grey dotted grey lines indicate lymphocytes, filled grey triangles and grey solid lines indicate monocytes. Note that significant positive correlation is observed in older men (R = 0.468/p = 0.005** and R = 0.492/p = 0.003**, for WBC and NC respectively).

Fig. 4

Correlations analysis between BMI and MAP, in young and older donors, split by CMV status.