الفهرس 
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Abstract
Leptin is an adipocyte-derived hormone involved in a myriad of
physiological process, including the control of energy balance and several
neuroendocrine axes. Leptin actions as a signal of energy sufficiency
under physiologic conditions, circulating levels of leptin are highly
correlated with stored adipocyte mass.
Leptin receptors are expressed in many organs and tissues,
including those related to the control of reproductive physiology (e.g., the
hypothalamus, pituitary gland, and gonads).
Ageing is also characterized by excess adiposity suggesting that
age might also be an important secondary regulator of plasma leptin.
Throughout the life cycle in men, the hormonal milieu changes
and is influenced in old age by adrenopause, somatopause and
andropause. Serum testosterone levels decrease with age, but this is a
very slow and long-lasting process, and therefore it is much more difficult
to correlate with symptoms which may not be easily differentiated from
an age-related physiologic decline in general health. Depression, fatigue,
lack of energy and cognitive symptoms are among the main non-specific
complaints, whereas flushes and sweats, decreased libido and erectile
dysfunction seem to be directly associated with hypogonadism. Another
important aspect is the ability to reverse the consequences of sex
hormone deprivation by a replacement therapy.
Testosterone has a suppressive effect on leptin production, as
reflected by circulating levels of this hormone. Furthermore, the plasma
leptin concentration was clearly suppressed during testosterone treatment
and returned to the pretreatment level after cessation of testosterone
treatment without concomitant changes in either BMI or serum insulin.
So we aimed by this work to study leptin and testosterone levels in
different age groups of healthy males.
To approach our goal we performed a study included 89 healthy
male volunteers classified according to age into 5 groups <10,10-<20,20-
<40,40-<60and≥60,each group include at least 15 persons. All subjects
included were given written, informed consent of approval of the
research. This study toke place from July 2011to December 2013. For
each volunteer, the following was done:
(1) Through history.
(2) Through general and local examination.
(3)Laboratory investigations for:
1- Plasma leptin level.
2- Total testosterone level.
The individuals having or exposed to any of the factors that might
affect total testosterone or leptin levels were excluded
The results showed that:
The results of the present study shows that there is significant
increase with age in the level of plasma leptin among the studied groups
while regarding plasma total testosterone level there is highly significant
increase of its level till group(4) followed by high significant decrease in
group (5) .
In concern of plasma leptin level the results shows a significant
correlation between group (1) and each of group (3), group (4) and group
(5) and between group(2) and group(5) but insignificant correlation
between other groups.
Regarding plasma total testosterone level there is significant
correlation between group (1) and group (2) and highly significant
correlation between group (1) all other groups . There is significant
correlation between group (3) and group (5) and between group (4) and
group(5) but insignificant correlation between other groups.
Also there is significant positive correlation between age and both
of plasma leptin and total testosterone among total participants and in
group (2). Insignificant positive correlation between age and both of
plasma leptin and total testosterone in group (1) , but insignificant
negative correlation between age and both of plasma leptin and total
testosterone in group (3)was found .There is also insignificant negative
correlation between age and plasma leptin in both group (4) and group(5)
as well as insignificant but positive correlation between age and total
testosterone in group (4) and a highly significant negative correlation
between age and total testosterone in group(5)was detected.
The results demonstrated a significant positive correlation between
plasma leptin and total testosterone among the total participants and in
group (2). There is insignificant positive correlation between plasma
leptin and total testosterone shown in both group(3) and group(4)as well
as insignificant but negative correlation detected in both group(1) and
group(5).