Is serum gamma-glutamyltransferase an exposure marker of xenobiotics?
Taken together with the previous epidemiological evidence, the associations of serum GGT with OH-PAHs reinforce the concept that serum GGT is a marker for various environmental pollutants encountered at background levels in the general population.
These data indicate that significantly higher leptin levels in Tanner stage 2 compared with prepuberty are not a prerequisite for progression into puberty. However, the absence of elevated leptin concentrations may be associated with delayed puberty in boys.