BMI in relation to sperm count: an updated systematic review and collaborative meta-analysis

TY - JOUR

T1 - BMI in relation to sperm count

T2 - an updated systematic review and collaborative meta-analysis

AU - Sermondade, N

AU - Faure, C

AU - Fezeu, L

AU - Shayeb, A G

AU - Bonde, J P

AU - Jensen, T K

AU - Van Wely, M

AU - Cao, J

AU - Martini, A C

AU - Eskandar, M

AU - Chavarro, J E

AU - Koloszar, S

AU - Twigt, J M

AU - Ramlau-Hansen, C H

AU - Borges, E

AU - Lotti, F

AU - Steegers-Theunissen, R P M

AU - Zorn, B

AU - Polotsky, A J

AU - La Vignera, S

AU - Eskenazi, B

AU - Tremellen, K

AU - Magnusdottir, E V

AU - Fejes, I

AU - Hercberg, S

AU - Lévy, R

AU - Czernichow, S

PY - 2013/5

Y1 - 2013/5

N2 - BACKGROUND The global obesity epidemic has paralleled a decrease in semen quality. Yet, the association between obesity and sperm parameters remains controversial. The purpose of this report was to update the evidence on the association between BMI and sperm count through a systematic review with meta-analysis. METHODS A systematic review of available literature (with no language restriction) was performed to investigate the impact of BMI on sperm count. Relevant studies published until June 2012 were identified from a Pubmed and EMBASE search. We also included unpublished data (n = 717 men) obtained from the Infertility Center of Bondy, France. Abstracts of relevant articles were examined and studies that could be included in this review were retrieved. Authors of relevant studies for the meta-analysis were contacted by email and asked to provide standardized data. RESULTS A total of 21 studies were included in the meta-analysis, resulting in a sample of 13 077 men from the general population and attending fertility clinics. Data were stratified according to the total sperm count as normozoospermia, oligozoospermia and azoospermia. Standardized weighted mean differences in sperm concentration did not differ significantly across BMI categories. There was a J-shaped relationship between BMI categories and risk of oligozoospermia or azoospermia. Compared with men of normal weight, the odds ratio (95% confidence interval) for oligozoospermia or azoospermia was 1.15 (0.93-1.43) for underweight, 1.11 (1.01-1.21) for overweight, 1.28 (1.06-1.55) for obese and 2.04 (1.59-2.62) for morbidly obese men. CONCLUSIONS Overweight and obesity were associated with an increased prevalence of azoospermia or oligozoospermia. The main limitation of this report is that studied populations varied, with men recruited from both the general population and infertile couples. Whether weight normalization could improve sperm parameters should be evaluated further.

AB - BACKGROUND The global obesity epidemic has paralleled a decrease in semen quality. Yet, the association between obesity and sperm parameters remains controversial. The purpose of this report was to update the evidence on the association between BMI and sperm count through a systematic review with meta-analysis. METHODS A systematic review of available literature (with no language restriction) was performed to investigate the impact of BMI on sperm count. Relevant studies published until June 2012 were identified from a Pubmed and EMBASE search. We also included unpublished data (n = 717 men) obtained from the Infertility Center of Bondy, France. Abstracts of relevant articles were examined and studies that could be included in this review were retrieved. Authors of relevant studies for the meta-analysis were contacted by email and asked to provide standardized data. RESULTS A total of 21 studies were included in the meta-analysis, resulting in a sample of 13 077 men from the general population and attending fertility clinics. Data were stratified according to the total sperm count as normozoospermia, oligozoospermia and azoospermia. Standardized weighted mean differences in sperm concentration did not differ significantly across BMI categories. There was a J-shaped relationship between BMI categories and risk of oligozoospermia or azoospermia. Compared with men of normal weight, the odds ratio (95% confidence interval) for oligozoospermia or azoospermia was 1.15 (0.93-1.43) for underweight, 1.11 (1.01-1.21) for overweight, 1.28 (1.06-1.55) for obese and 2.04 (1.59-2.62) for morbidly obese men. CONCLUSIONS Overweight and obesity were associated with an increased prevalence of azoospermia or oligozoospermia. The main limitation of this report is that studied populations varied, with men recruited from both the general population and infertile couples. Whether weight normalization could improve sperm parameters should be evaluated further.

KW - Azoospermia

KW - Body Mass Index

KW - Body Weight

KW - Fertility

KW - France

KW - Humans

KW - Male

KW - Obesity

KW - Odds Ratio

KW - Oligospermia

KW - Overweight

KW - Semen Analysis

KW - Sperm Count

KW - Spermatozoa

U2 - 10.1093/humupd/dms050

DO - 10.1093/humupd/dms050

M3 - Journal article

C2 - 23242914

SN - 1355-4786

VL - 19

SP - 221

EP - 231

JO - Human Reproduction Update

JF - Human Reproduction Update

IS - 3

ER -