Sex and Body Circumferences Associated with Serum Leptin in African American Adults

Unveiling the causal link between metabolic factors and ovarian cancer risk using Mendelian randomization analysis

Background

Metabolic abnormalities are closely tied to the development of ovarian cancer (OC), yet the relationship between anthropometric indicators as risk indicators for metabolic abnormalities and OC lacks consistency.

Method

The Mendelian randomization (MR) approach is a widely used methodology for determining causal relationships. Our study employed summary statistics from the genome-wide association studies (GWAS), and we used inverse variance weighting (IVW) together with MR-Egger and weighted median (WM) supplementary analyses to assess causal relationships between exposure and outcome. Furthermore, additional sensitivity studies, such as leave-one-out analyses and MR-PRESSO were used to assess the stability of the associations.

Result

The IVW findings demonstrated a causal associations between 10 metabolic factors and an increased risk of OC. Including "Basal metabolic rate" (OR= 1.24, P= 6.86×10-4); "Body fat percentage" (OR= 1.22, P= 8.20×10-3); "Hip circumference" (OR= 1.20, P= 5.92×10-4); "Trunk fat mass" (OR= 1.15, P= 1.03×10-2); "Trunk fat percentage" (OR= 1.25, P= 8.55×10-4); "Waist circumference" (OR= 1.23, P= 3.28×10-3); "Weight" (OR= 1.21, P= 9.82×10-4); "Whole body fat mass" (OR= 1.21, P= 4.90×10-4); "Whole body fat-free mass" (OR= 1.19, P= 4.11×10-3) and "Whole body water mass" (OR= 1.21, P= 1.85×10-3).

Conclusion

Several metabolic markers linked to altered fat accumulation and distribution are significantly associated with an increased risk of OC.

Blood Pressure Correlates with Serum Leptin and Body Mass Index in Overweight Male Saudi Students

The precise association of serum leptin (Lep) with the body mass index (BMI) and blood pressure (BP) is not well known for understanding their involvement in health and disease. Hence, the present study was conducted to investigate the association of BP, BMI and serum Lep levels in young normal-weight (NW) and overweight (OW) male Saudi students. The NW (n: 198) and OW (n: 192) male subjects in the age range of 18-20 years were consulted. The BP was measured with a mercury sphygmomanometer. Leptin Human ELISA Kits were employed for the determination of the serum Lep levels. The mean ± SD values of BMI (kg/m²), Lep (ng/mL), systolic BP (SBP; mmHg), and diastolic BP (DBP; mmHg) all showed significant differences for young OW vs. NW subjects as: 27.52 ± 1.42 vs. 21.49 ± 2.03; 10.70 ± 4.67 vs. 4.68 ± 1.91; 121.37 ± 2.59 vs. 118.51 ± 1.54 and 81.44 ± 1.97 vs. 78.79 ± 1.44, respectively. All associations (among BMI, Lep, SBP and DBP) showed a positive linear and significant correlation, except the nonsignificant correlation of BMI and SBP for the NW group. Other variables showing significant variation for NW vs. OW subjects were: interleukin-6, high sensitivity C-reactive protein, apelin (APLN) and resistin. Serum APLN correlated significantly with Lep, BMI, SBP and DBP in lower and higher levels of BMI, with considerable progressive patterns in both the NW and OW groups and subgroups. The present study in young Saudi male students presents significant variations for BP and serum leptin levels, and a significant positive linear association among serum leptin, BMI and BP.

Lower Life Satisfaction and Inflammation in African American Adults: Body Adiposity Mediation and Sex Moderation

Both lower life satisfaction (LLS) and chronic inflammation are underlying conditions for numerous diseases. We investigated their associations in African American adults, within the context of three hypotheses: (a) perceived LLS will be positively associated with inflammation measured by serum C-reactive protein (CRP); (b) this association will be mediated by body adiposity; and (c) these associations will be moderated by sex. Participants (n = 83; >45 years; 59% women) were a subsample of a larger church-based intervention to reduce cardiovascular risks and were assessed at baseline and after 6 months. Body adiposity (BMI/hip/waist circumferences) was measured by standardized methods and CRP with ELISA. LLS was self-reported. The analyses were conducted in the structural equation modeling (SEM) framework. The direct relationship between LLS and CRP was significant for all participants but was mediated by BMI/hip/waist circumferences. Multi-group SEM analysis provided evidence for sex moderation by showing that the mediating pathway from LLS to CRP through BMI, and to a lesser extent through hip/waist circumferences, was significant only in women. In conclusion, perceived LLS was positively associated with the level of inflammation mediated by BMI/hip/waist circumference, with the association between LLS and CRP being stronger in women. These findings contribute to the current literature untangling mediation/moderation processes in which perceived LLS may contribute to adiposity-related inflammation. They also add to precision medicine development, suggesting that stress and inflammation-reducing interventions should focus on African Americans, particularly women.