Biological Trace Element Research

, Volume 91, Issue 2, pp 137–144 | Cite as

Serum copper levels and not zinc are positively associated with serum leptin concentrations in the healthy adult population

  • Samuel Olusi
  • Adel Al-Awadhi
  • Clifford Abiaka
  • Mathew Abraham
  • Sunila George


Leptin, the obesity gene protein product, is a hormone with multiple physiological functions in the human. However, there are few reports in the literature on its role in trace element metabolism in the normal population. Therefore, we investigated the association among serum leptin, zinc, copper, and zinc/copper ratio in 570 healthy men and women aged 15 yr and older. Serum leptin assay was done with a commercial enzymelinked immunosorbent assay kit; serum zinc and copper levels were measured by an atomic absorption spectrophotometer. Serum leptin was found to be positively associated with age (r=0.254, p<0.001), sex (r=0.406, p<0.001), body mass index (BMI) (r=0.553, p<0.001), and serum copper (r=0.419, p<0.001), but negatively associated with the zinc/copper ratio (r=−0.423, p<0.001). There was no significant association between serum leptin and zinc (r=−0.131, p>0.05). When the confounding effects of age, sex, and BMI were removed, serum leptin was still positively associated with serum copper (r=0.197, p=0.02) and the serum zinc/copper ratio (r=−0.182, p=0.03). These results suggest that copper and not zinc has an effect on serum leptin levels.

Index Entries

Serum leptin copper zinc zinc/copper ratio normal population 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Y. Zhang, R. Proenca, M. Maffei, et al., Positional cloning of the mouse ob gene and its human homologue, Nature 372, 425–432 (1994).PubMedCrossRefGoogle Scholar
  2. 2.
    J. L. Halaas, K. S. Gajiwala, M. Maffei, et al., Weight reducing effects of the plasma protein encoded by the obese gene, Science 269, 543–546 (1995).PubMedCrossRefGoogle Scholar
  3. 3.
    R. C. Frederich, A. Hamann, S. Anderson, et al., Leptin reflects body lipid content in mice: evidence for diet-induced leptin resistance, Nat. Med. 1, 1311–1314 (1995).PubMedCrossRefGoogle Scholar
  4. 4.
    M. Maffei, J. Halaas, E. Ravussin, et al., Leptin levels in human and rodent: measurement of plasma leptin and ob RNA in obese and weight-reduced subjects, Nat. Med. 1, 1555–1561 (1995).CrossRefGoogle Scholar
  5. 5.
    H. Masuzaki, Y. Ogawa, K. Hosoda, et al., Augmented expression of the obese gene in the adipose tissue from rats fed high-fat-diet, Biochem. Biophys. Res. Commun. 216, 355–358 (1995).PubMedCrossRefGoogle Scholar
  6. 6.
    L. A. Campfield, F. J. Smith, and P. Burn, The ob protein (leptin) pathway—a link between adipose tissue mass and central neural networks, Horm. Metab. Res. 28, 619–632 (1996).PubMedCrossRefGoogle Scholar
  7. 7.
    F. Chehab, K. Mounzih, and R. Lu, Early onset of reproductive function in normal female mice treated with leptin, Science 275, 88–90 (1997).PubMedCrossRefGoogle Scholar
  8. 8.
    F. F. Chehab, M. F. Lim, and R. Lu, Correlation of the sterility defect in homozygous obese female mice in treatment with the human recombinant leptin, Nat. Genet. 12, 318–320 (1996).PubMedCrossRefGoogle Scholar
  9. 9.
    I. A. Barash, C. C. Cheung, D. S. Weigle, et al., Leptin is a metabolic signal to the reproductive system, Endocrinology 137, 3144–3147 (1996).PubMedCrossRefGoogle Scholar
  10. 10.
    T. Gainsford, T. A. Wilson, D. Metcalf, et al., Leptin can induce proliferation, differentiation, and functional activation of the hemopoietic cells, Proc. Natl. Acad. Sci. USA 93, 14,564–14,568 (1996).CrossRefGoogle Scholar
  11. 11.
    G. M. Lord, G. Matarese, J. K. Howard, et al., Leptin modulates the T-cells immune response and reverses starvation induced immuno-suppression, Nature 394, 89–97 (1998).Google Scholar
  12. 12.
    C. Liu, A. Grossman, S. Bain, et al., Leptin stimulates cortical bone formation in obese mice, J. Bone Miner. Res. 12(Suppl. 1), s115 (1997).Google Scholar
  13. 13.
    C. Abiaka, S. O. Olusi, and A. M. Al-Awadhi, Age, and sex-specific reference range for serum copper and zinc in an adult Arab population, in press.Google Scholar
  14. 14.
    J. M. Hsu, in Zinc and Copper in Medicine, Z. A. Karcioglu and R. M. Sarper, eds., Charles C Thomas, Springfield, IL, pp. 66–93 (1980).Google Scholar
  15. 15.
    C. S. Mantzoros, A. S. Prasad, F.W.J. Beck, et al., Zinc may regulate serum leptin concentrations in humans, J. Am. Coll. Nutr. 17, 270–275 (1998).PubMedGoogle Scholar
  16. 16.
    M. D. Chen, Y. M. Song, C. T. Tsou, et al., Leptin concentration and the Zn/Cu ratio in plasma in women with thyroid disorder, Biol. Trace Element Res. 75, 99–105 (2000).CrossRefGoogle Scholar

Copyright information

© Humana Press Inc. 2003

Authors and Affiliations

  • Samuel Olusi
    • 1
  • Adel Al-Awadhi
    • 2
  • Clifford Abiaka
    • 3
  • Mathew Abraham
    • 1
  • Sunila George
    • 1
  1. 1.Department of PathologyKuwait UniversitySafatKuwait
  2. 2.Department of Medicine, Faculty of MedicineKuwait UniversitySafatKuwait
  3. 3.Department of Medical Laboratory Science, Faculty of Allied Health Sciences and NursingKuwait UniversitySafatKuwait

Personalised recommendations