**5. Conclusions**

Based on our results, we may conclude that the association of the *PLIN1* and *PLIN2* polymorphisms with BMI, NEFA, and Apo A-I concentrations seems to be modulated by plasma leptin levels in prepubertal children. Our data may contribute to elucidate the discrepancies observed in previous studies analyzing these associations in adult populations. Our data allow us to speculate that different plasma leptin concentration by sex through life, affecting the relationship of the *PLIN* SNPs with cardiovascular risk factors, such as BMI and lipid profile, may contribute to explaining the different predisposition to cardiovascular disease depending on sex across life. Further studies analyzing these aspects in other groups of age should be performed.

**Supplementary Materials:** The following supporting information can be downloaded at: https://www. mdpi.com/article/10.3390/nu14153072/s1, Figure S1: (**a**) HDL-cholesterol levels of *PLIN1*rs894160 genotypes in boys and girls according to levels of leptin; (**b**) HDL-cholesterol levels of *PLIN2*rs35568725 genotypes in boys and girls by leptin levels. Values are expressed as median and interquartile range. *p*-value: Mann–Whitney U test: \* *p*-value< 0.05; \*\* *p*-value < 0.01.

**Author Contributions:** Conceptualization, C.G.; methodology, C.V.-V., I.P.-N. and O.d.D.; software, C.V.-V. and J.L.-C.; formal analysis, C.V.-V., J.L.-C. and C.G.; investigation, C.V.-V., I.P.-N. and O.d.D.; resources, T.G.-P., L.S.-G. and C.G.; data curation, T.G.-P. and C.G; writing—original draft preparation, C.G.; writing—review and editing, C.V.-V., J.L.-C., T.G.-P. and L.S.-G.; visualization, C.V.-V. and J.L.-C.; supervision, C.G.; project administration, C.G.; funding acquisition, L.S.-G. and C.G. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported by a gran<sup>t</sup> from the Fondo de Investigación Sanitaria (FIS 18/01016) and Biobank gran<sup>t</sup> FEDER RD09/0076/00101. Claudia Vales-Villamarín is recipient of a research contract from Carlos III Institute of Health (pFIS). Jairo Lumpuy-Castillo received gran<sup>t</sup> support in the form of an FPI contract from Universidad Autónoma, Madrid.

**Institutional Review Board Statement:** The study was conducted in accordance with the Declaration of Helsinki, and approved by the Clinical Research Ethics Committee of the IIS-Fundación Jiménez Díaz (PIC016-2019 FJD).

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** The article is dedicated to the late Manuel de Oya as the warmest homage to his memory. We thank Oliver Shaw for his assistance with language editing.

**Conflicts of Interest:** The authors declare no conflict of interest.
