Phthalate exposure and reproductive hormones in adult men.
BACKGROUND
Phthalates are used in personal and consumer products, food packaging materials, and polyvinyl chloride plastics and have been measured in the majority of the general population of the USA. Consistent experimental evidence shows that some phthalates are developmental and reproductive toxicants in animals. This study explored the association between environmental levels of phthalates and altered reproductive hormone levels in adult men.


METHODS
Between 1999 and 2003, 295 men were recruited from Massachusetts General Hospital. Selected phthalate metabolites were measured in urine. Linear regression models explored the relationship between specific gravity-adjusted urinary phthalate monoester concentrations and serum levels of reproductive hormones, including FSH, LH, sex hormone-binding globulin, testosterone, and inhibin B.


RESULTS
An interquartile range (IQR) change in monobenzyl phthalate (MBzP) exposure was significantly associated with a 10% [95% confidence interval (CI): -16, -4.0] decrease in FSH concentration. Additionally, an IQR change in monobutyl phthalate (MBP) exposure was associated with a 4.8% (95% CI: 0, 10) increase in inhibin B but this was of borderline significance.


CONCLUSIONS
Although we found associations between MBP and MBzP urinary concentrations and altered levels of inhibin B and FSH, the hormone concentrations did not change in the expected patterns. Therefore, it is unclear whether these associations represent physiologically relevant alterations in these hormones, or whether they represent associations found as a result of conducting multiple comparisons.
Duty
Susan M
SM
Environmental Health Department, Occupational Health Program, Harvard School of Public Health, Boston, MA 02115, USA.
Calafat
Antonia M
AM
Silva
Manori J
MJ
Ryan
Louise
L
Hauser
Russ
R
D000328:Adult; D004781:Environmental Exposure; D005640:Follicle Stimulating Hormone / Q000097:blood; D006728:Hormones / Q000097:blood*; D006801:Humans; D007265:Inhibins / Q000097:blood; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D010795:Phthalic Acids / Q000009:adverse effects* / Q000652:urine*; D012044:Regression Analysis; D012098:Reproduction / Q000502:physiology*
D006728:Hormones; D010795:Phthalic Acids; C422364:inhibin B; C103325:mono-benzyl phthalate; D007265:Inhibins; D005640:Follicle Stimulating Hormone; C028577:monobutyl phthalate