219Archivio Italiano di Urologia e Andrologia 2017; 89, 3

ORIGINAL PAPER

Investigation of the effect of body mass index (BMI) on 
semen parameters and male reproductive system hormones

Mehmet Zeynel Keskin 1, Salih Budak 1, Evrim Emre Aksoy 2, Cem Yücel 1, Serkan Karamazak 1, 
Yusuf Ozlem Ilbey 1, Zafer Kozacıoğlu 1

1 Tepecik Training and Research Hospital, Izmir, Turkey;
2 Kırkağaç State Hospital, Manisa, Turkey.

Aim: To evaluate the effects of body mass
index (BMI) ratio on semen parameters and

serum reproductive hormones.
Materials and methods: The data of 454 patients who prsented
to male infertility clinics in our hospital between 2014 and
2015 were analyzed retrospectively. Weight, height, serum
hormone levels and semen analysis results of the patients were
obtained. BMI values were calculated by using the weight and
height values of the patients and they were classified as group
1 for BMI values ≤ 25 kg/m2, as group 2 for BMI values 25-30
kg/m2 and as group 3 for BMI values ≥ 30 kg/m2.
Results: The mean values of BMI, semen volume, concentra-
tion, total motility, progressive motility, total progressive
motile sperm count (TPMSC), normal morphology according to
Kruger, head abnormality, neck abnormality, tail abnormality,
FSH, LH, prolactin, T/E2, total testosterone and estradiol
parameters of the patients were considered. 
Patients were divided according to BMI values in Group 1
(n = 165), Group 2 (n = 222) and Group 3 (n = 56). 
There was no statistically significant difference in terms of all
variables between the groups. 
Conclusions: We analyzed the relationship between BMI level
and semen parameters and reproductive hormones, demonstrat-
ing no relationship between BMI and semen parameters. In our
study, BMI does not affect semen parameters although it shows
negative correlation with prolactin and testosterone  levels. 

KEY WORDS: Infertility; BMI; Semen  parameters; Reproductive
hormones.

Submitted 18 May 2016; Accepted 19 August 2016 

Summary

No conflict of interest declared.

number of studies and in some studies this decrease was
found as associated to the increase in obesity prevalence
(2). But, there is not a consensus in the literature and
contradictory results were published. In this study, we
analyzed the effect of BMI on semen parameters and the
relationship with reproductive hormone levels.          

MATERIALS AND METHODS
The data of 454 patients who presented to male infertil-
ity clinics in our hospital between 2014 and 2015 were
analyzed retrospectively. Weight, height, serum hormone
levels and semen analysis results of the patients were
considered. BMI values were calculated by using the
weight and height values of the patients and they were
classified as Group 1 for BMI values ≤ 25 kg/m2, as
Group 2 for BMI values 25-30 kg/m2 and as Group 3 for
BMI values ≥ 30 kg/m2.
Semen analysis was performed after a 3-5 days of sexual
abstinence. Semen analysis was performed according to
WHO 2010 criteria (semen volume ≥ 1.5 ml; sperm con-
centration ≥ 15 × 106/ml; total motility ≥ 40%, progressive
motility ≥ 32% and morphology ≥ 4%). After 5-30 minutes
of sample collection, the analysis was performed after the
sample was liquefied. For the microscopic examination in
semen analysis, phase contrast light microscope was used
and the examination was performed with 10 x 20 magnifi-
cation. For sperm concentration, Makler counting chamber
was used and the sperm count (concentration) was found
in million/ml with the sperm count in 10 squares in a 100
square area. Motility was evaluated in 3 Groups as linear
progressive motility, non-progressive motility and immotil-
ity. For the morphological examination, semen sample
which was dropped on slides, washed with 70% alcohol
previously, according to sperm concentration were dried
with 45 degrees angle. Then, it was stained with Diff-
Quick kit and at least 200 sperm were analyzed under
immersion oil with 100X objective and the percentage of
the sperm having normal morphology was determined.
For the hormone levels, blood sample was collected in the
morning before 10.00 a.m. Hormone analysis was per-
formed with Roche Hitachi Cobase 601 equipment and by
using microparticle enzyme immunoassay method. FSH,
LH, prolactin, total testosterone and estradiol levels were
analyzed. The statistical analysis was performed with IBM
Statistical Package for Social Sciences (SPSS) Version 22.0

DOI: 10.4081/aiua.2017.3.219

INTRODUCTION
Being overweight and obesity are among the most signifi-
cant health problems in our era. World Health Organization
(WHO) described as overweight a patient with body mass
index (BMI) ≥ 25 kg/m2 and as obese a patient with BMI ≥
30 kg/m. According to WHO data, 35% of the young
patients, who are in their twenties, are overweight and
11% of them are obese (1). It was reported that the over-
weight and obesity incidence dramatically increased in
developed countries in last 30 years (2). 
Infertility is another health problem affecting 15% of the
couples in developed countries (3). A significant
decrease in the sperm quality was shown by studies con-
ducted in last 25 years (4, 5). The reason of this decrease
aroused interest and it became a subject for research.
Especially, its relation with the obesity was analyzed in a

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Archivio Italiano di Urologia e Andrologia 2017; 89, 3

M. Zeynel Keskin, S. Budak, E. Emre Aksoy, C. Yücel, S. Karamazak, Y. Ozlem Ilbey, Z. Kozacıoğlu

220

programme. A value of p < 0.05 was
accepted as statistically significant. 

RESULTS
The mean values of BMI, semen vol-
ume, concentration, total motility, pro-
gressive motility, total progressive motile
sperm count (TPMSC), normal mor-
phology according to Kruger, head
abnormality, neck abnormality, tail
abnormality, FSH, LH, prolactin, T/E2,
total testosterone and estradiol param-
eters of the patients are shown in
Table 1. Patients were divided accord-
ing to BMI values in Group 1 (n =
165), Group 2 (n = 222) and Group 3
(n = 56).  There was no statistically
significant difference in semen
parameters between the groups. BMI
ratio do not affect semen parameters
but it shows negative correlation with
prolactin and total testosterone.

DISCUSSION
The effect of obesity on semen param-
eters is multifactorial and it was tried
to be explained with different patho-
physiological mechanisms (6, 7). 
The fact that testosterone is aromatized
to estradiol (E2) in fat tissue (8), the
decrease in sex hormone binding globulin
(SHBG) levels (9), the suppression of
luteinizing hormone (LH) secretion with
the increase of endorphin levels (10),
hyperinsulinemia and hyperlipidemia
(11) were found as responsible for this
relationship, although there are con-
tradictory results in the literature. 
In a meta-analysis conducted by
MacDonald et al., no relationship
between semen parameters and BMI
was detected (12). Moreover, in other
similar original studies, this relation-
ship was not found (13, 14). On the
contrary, in a meta-analysis conducted
by Sermondade et al., a negative rela-
tionship between BMI and semen
parameters was detected (7). There are
also original studies reporting similar
results (15-17). While a statistically
significant negative relationship was
detected between BMI and semen vol-
ume, concentration and motility in a
comprehensive cohort study including
10665 patients conducted by Belloc

Table 1. 
Mean volues of data and p values
according to BMI groups.

BMI
Parameter < 25.0 kg/m2 25.0-30.0 kg/m2 > 30.0 kg/m2 p value
BMI (kg/m2)  

Minimum 18.78 25.01 30.04
Maximum 24.98 29.98 43.55
Mean 22.65 27.06 33.09
Std. Dev. 1.69 1.35 3.44

Volume (mL) 0.330
Minimum 0 0 0
Maximum 11 8 8
Mean 2.88 2.69 2.58
Std. Dev. 1.71 1.67 1.65

Concentration (106/mL) 0.576
Minimum 0 0 0
Maximum 168 170 140
Mean 33.28 35.56 33.74
Std. Dev. 36.91 36.29 35.59

Total motility (%) 0.754
Minimum 0 0 0
Maximum 85 85 90
Mean 46.34 49.76 47.63
Std. Dev. 25.29 22.22 27.26

Progressive motility (%) 0.694
Minimum 0 0 0
Maximum 80 94 80
Mean 30.15 31.94 30.66
Std. Dev. 21.89 21.55 22.91

TPMSC (Million) 0.790
Minimum 0 0 0
Maximum 352.8 361.08 220
Mean 40.66 44.40 41.97
Std. Dev. 59.97 62.83 56.67

Normal morphology (Kruger) (%) 0.554
Minimum 0 0 0
Maximum 10 9 7
Mean 2.43 2.60 2.26
Std. Dev. 2.23 2.12 2.00

Head abnormality (%) 1.000
Minimum 0 0 0
Maximum 100 91 86
Mean 50.16 51.75 48.20
Std. Dev. 39.93 38.41 40.82

Neck abnormality (%) 0.937
Minimum 0 0 0
Maximum 14 14 14
Mean 5.72 6.15 6
Std. Dev. 5.12 4.89 5.29

Tail abnormality (%) 0.561
Minimum 0 0 0
Maximum 11 13 14
Mean 4.16 4.66 3.80
Std. Dev. 3.86 3.94 4.02

FSH (mIU/mL) 0.299
Minimum 1.56 1.57 1.68
Maximum 31 44.72 17.15
Mean 3.42 2.76 2.18
Std. Dev. 5.58 2.18 3.74

LH (mIU/mL) 0.452
Minimum 2 1.63 2.02
Maximum 14.63 19.57 16.87
Mean 5.61 5.29 6.04
Std. Dev. 2.74 5.72 3.22

Prolactin (ng/mL) 0.018
Minimum 3.35 2.98 5.83
Maximum 27.85 49.29 27.04
Mean 11.44 9.87 10.88
Std. Dev. 5.51 5.84 4.37

T/E ratio (%) 0.815
Minimum 6.98 2.05 8.31
Maximum 22.16 39.13 14.87
Mean 11.82 15.49 11.59
Std. Dev. 8.26 9.77 4.63

Testosterone (ng/dL) 0.001
Minimum 9.1 4.31 147.10
Maximum 851.7 856 676.20
Mean 488.32 398.20 377.61
Std. Dev. 175.13 139.71 113.36

Estradiol (pg/mL) 0.270
Minimum 16.32 7.21 32.76
Maximum 44.24 160.30 57.29
Mean 29.88 34.93 45.02
Std. Dev. 9.87 37.12 17.34

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et al., no relationship with morphology was detected (18).
In another study with 42 patients conducted by Leisegang
et al., it was reported that BMI level and sperm concentra-
tion are negatively correlated and no correlation was
detected with motility and morphology (19). In a cohort
study, which Stewart et al. conducted with 225 fertile male
patients, it was reported that BMI and sperm count are
negatively correlated (20). In our study, no statistically sig-
nificant relationship was found between BMI level and
semen parameters. In a recent study, on the other hand,
the relationship between BMI and semen parameters and
reproductive hormone levels was analyzed and a statisti-
cally significant negative relationship between BMI and
semen volume, SHBG and total Testosterone (T) level was
detected (21). In the study conducted by Relwani et al., it
was reported that BMI level does not affect semen param-
eters but it statistically significantly decreases T, SHBG and
free T level (22). In the literature, there is a general con-
sideration that obesity especially decreases total testos-
terone and SHBG levels but it is partially correlated to free
testosterone levels (16, 23). In our study, we observed that
when BMI level is high, prolactin and total testosterone
levels are significantly lower.

CONCLUSIONS
In our study, when we analyzed the relationship between
BMI level and semen parameters and reproductive hor-
mones, no relationship was detected between BMI and
semen parameters. On the contrary BMI level shows a neg-
ative correlation with prolactin and testosterone levels.
However, to reveal the relationship between BMI and male
infertility, large, randomized and prospective studies are
needed.

REFERENCES
1. Joint WHO/FAO Expert Consultation. Diet, nutrition and the pre-
vention of chronic diseases. WHO Technical Report Series 916.
World Health Organization, Geneva; 2003.

2. Finucane MM, Stevens GA, Cowan MJ, et al. Global Burden of
Metabolic Risk Factors of Chronic Diseases Collaborating Group
(Body Mass Index). National, regional, and global trends in body-
mass index since 1980: systematic analysis of health examination
surveys and epidemiological studies with 960 country-years and 9.1
million participants. Lancet. 2011; 377:557-567.

3. Eisenberg ML, Kim S, Chen Z, et al. The relationship between
male BMI and waist circumference on semen quality: data from the
LIFE study. Hum Reprod. 2014; 29:193-200.

4. Carlsen E, Giwercman A, Keiding N, Skakkebaek NE. Evidence
for decreasing quality of semen during past 50 years. Br Med J.
1992; 305:609-613.

5. Swan SH, Elkin EP. Declining semen quality: can the past inform
the present? Bioessays 1999; 21:614-621.

6. Eisenberg ML, Kim S, Chen Z, et al. The relationship between
male BMI and waist circumference on semen quality: data from the
LIFE study. Hum Reprod. 2015; 30:493-4.

7. Sermondade N, Faure C, Fezeu L, et al. BMI in relation to sperm
count: an updated systematic review and collaborative meta-analy-
sis. Hum Reprod Update. 2013; 19:221-231.

8. Schneider G, Kirschner MA, Berkowitz R, Ertel NH. Increased

estrogen production in obese men. J Clin Endocrinol Metab. 1979;
48:633-638.

9. Stellato RK, Feldman HA, Hamdy O, et al. Testosterone, sex hor-
mone-binding globulin, and the development of type 2 diabetes in
middle-aged men: prospective results from the Massachusetts male
aging study. Diabetes Care. 2000; 23:490-494.

10. Blank DM, Clark RV, Heymsfield SB, et al. Endogenous opioids and
hypogonadism in human obesity. Brain Res Bull. 1994; 34:571-574.

11. Lampiao F, du Plessis SS. Insulin and leptin enhance human
sperm motility, acrosome reaction and nitric oxide production. Asian
J Androl. 2008; 10:799-807.

12. MacDonald AA, Herbison GP, Showell M, Farquhar CM. The
impact of body mass index on semen parameters and reproductive
hormones in human males: a systematic review with meta-analysis.
Hum Reprod Update. 2010; 16:293-311.

13. Aggerholm AS, Thulstrup AM, Toft G, et al. Is overweight a risk
factor for reduced semen quality and altered serum sex hormone
profile? Fertil Steril. 2008; 90:619-626.

14. Li Y, Lin H, Ma M, et al. Semen quality of 1346 healthy men,
results from the Chongqing area of southwest China. Hum Reprod.
2009; 24:459-469.

15. Jensen TK, Andersson AM, Jørgensen N, et al. Body mass index
in relation to semen quality and reproductive hormones among
1,558 Danish men. Fertil Steril. 2004; 82:863-870.

16. Erdemir F. Relationship Between Obesity and Male Infertility. J
Clin Anal Med. 2013; 4:76-82.

17. Hofny ER, Ali ME, Abdel-Hafez HZ, et al. Semen parameters
and hormonal profile in obese fertile and infertile males. Fertil
Steril. 2010; 94:581-584.

18. Belloc S, Cohen-Bacrie M, Amar E, et al. High body mass index
has a deleterious effect on semen parameters except morphology:
results from a large cohort study. Fertil Steril. 2014; 102:1268-73.

19. Leisegang K, Bouic PJ, Menkveld R, Henkel RR. Obesity is asso-
ciated with increased seminal insulin and leptin alongside reduced
fertility parameters in a controlled male cohort. Reprod Biol
Endocrinol. 2014; 12:34:2-12.

20. Stewart TM, Liu DY, Garrett C, et al. Associations between
andrological measures, hormones and semen quality in fertile
Australian men: inverse relationship between obesity and sperm out-
put. Hum Reprod. 2009; 24:1561-1568.

21. Ehala-Aleksejev K, Punab M. The different surrogate measures of
adiposity in relation to semen quality and serum reproductive hormone
levels among Estonian fertile men. Andrology. 2015; 3:225-234.

22. Relwani R, Berger D, Santoro N, et al. Jindal Semen parameters
are unrelated to BMI but vary with SSRI use and prior urological
surgery. Reprod Sci. 2011; 18:391-7.

23. Allen NE, Appleby PN, Davey GK, Key TJ. Lifestyle and nutri-
tional determinants of bioavailable androgens and related hormones
in British men. Cancer Causes Control. 2002; 13:353-63.

221Archivio Italiano di Urologia e Andrologia 2017; 89, 3

Investigation of the effect of body mass index (BMI) on semen parameters and male reproductive system hormones

Correspondence
Mehmet Zeynel Keskin, MD (Corresponding Author)
zeynel_akd@hotmail.com 
Salih Budak, MD - salihbudak1977@gmail.com 
Cem Yücel, MD - meclecuy@hotmail.com 
Serkan Karamazak, MD - drkaramazak@hotmail.com
Yusuf Ozlem Ilbey, MD - ozlemyusufilbey@hotmail.com
Zafer Kozacıoğlu, MD - drzafko@hotmail.com
Tepecik Training and Research Hospital, Izmir, Turkey

Evrim Emre Aksoy, MD - dreaksoy@yahoo.com
Kırkağaç State Hospital, Manisa, Turkey

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