Sex differences in the associations of body size and body shape with platelets in the UK Biobank cohort

Abstract

Background Obesity is accompanied by low-grade inflammation and leucocytosis and increases the risk of venous thromboembolism. Associations with platelet count, however, are unclear, because several studies have reported positive associations only in women. Associations with body shape are also unclear, because waist and hip circumferences reflect overall body size, as well as body shape, and are correlated strongly positively with body mass index (BMI). Methods We evaluated body shape with the allometric body shape index (ABSI) and hip index (HI), which reflect waist and hip size among individuals with the same weight and height and are uncorrelated with BMI. We examined the associations of BMI, ABSI, and HI with platelet count, mean platelet volume (MPV), and platelet distribution width (PDW) in multivariable linear regression models for 125,435 UK Biobank women and 114,760 men. We compared men with women, post-menopausal with pre-menopausal women, and older (≥ 52 years) with younger (< 52 years) men. Results BMI was associated positively with platelet count in women, more strongly in pre-menopausal than in post-menopausal, and weakly positively in younger men but strongly inversely in older men. Associations of BMI with platelet count were shifted towards the inverse direction for daily alcohol consumption and current smoking, resulting in weaker positive associations in women and stronger inverse associations in men, compared to alcohol ≤ 3 times/month and never smoking. BMI was associated inversely with MPV and PDW in pre-menopausal women but positively in post-menopausal women and in men. ABSI was associated positively with platelet count, similarly in women and men, while HI was associated weakly inversely only in women. ABSI was associated inversely and HI positively with MPV but not with PDW and only in women. Platelet count was correlated inversely with platelet size and positively with leucocyte counts, most strongly with neutrophils. Conclusions Competing factors determine the associations of BMI with platelet count. Factors with sexually dimorphic action (likely thrombopoietin, inflammatory cytokines, or cortisol), contribute to a positive association, more prominently in women than in men, while age-dependent factors (likely related to liver damage and fibrosis), contribute to an inverse association, more prominently in men than in women.

Interactions of platelets with obesity in relation to lung cancer risk in the UK Biobank cohort

“…PLT and MPV were lower in men, while PDW was lower in women. MPV and PDW were correlated inversely with PLT and positively with each other, as previously reported [ 10 ].…”

“…We examined as exposures platelet parameters (PLT, MPV, or PDW) on a standardised continuous scale (z-scores, value minus mean, divided by standard deviation (SD) after log-transformation), interpreting hazard ratios (HR) per one SD increase. We examined men and women separately, due to the pronounced sex differences in the associations of obesity with platelet parameters [ 10 ]. We examined platelet parameters individually, because they are correlated substantially with each other [ 10 ] and could be biologically related and hence not independent.…”

“…We examined men and women separately, due to the pronounced sex differences in the associations of obesity with platelet parameters [ 10 ]. We examined platelet parameters individually, because they are correlated substantially with each other [ 10 ] and could be biologically related and hence not independent.…”

“…Although general obesity, as reflected in body mass index (BMI), is associated with higher risk of venous thromboembolism [ 7 ], BMI shows an inverse, smoking-related association with lung cancer risk [ 8 , 9 ]. Moreover, we have previously shown in UK Biobank that BMI is associated positively with PLT only in women, most strongly in never smokers, but inversely in men, most strongly in ever smokers [ 10 ]. This raises the question whether PLT interacts with obesity in relation to lung cancer risk.…”

Effectiveness of Bay Leaves (Syzygium polyanthum) to Reduce Body Mass Index Among Pre-Menopausal Obese Adults in South Jakarta Regency

“…The association between obesity and heart failure, as well as the differential risk patterns observed in pre-menopausal and postmenopausal women, highlights the nuanced relationship between obesity and cardiovascular health (Leedy et al, 2021). Obesity has been linked to low-grade inflammation, leucocytosis, and an increased risk of venous thromboembolism, emphasizing the broader health implications of obesity (Christakoudi et al, 2023).…”