Young Men with Type 2 Diabetes Have Low Testosterone

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Young Men With Type 2 Diabetes Have Low Testosterone

By Todd Neale, Staff Writer, MedPage Today

Published: September 05, 2008

Reviewed by Jasmer, MD; Associate Clinical Professor of

Medicine, University of California, San Francisco Earn CME/CE credit

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BUFFALO, N.Y., Sept. 5 -- Young men with type 2 diabetes have low

levels of testosterone, leaving them at risk for infertility,

atherosclerosis, and other health problems, according to a cross-

sectional study. Action Points

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Explain to interested patients that this study found that men ages 18

to 35 who had type 2 diabetes had significantly decreased levels of

testosterone, which the researchers said may result in myriad health

problems.

Among diabetic men ages 18 to 35, total testosterone concentrations

were significantly lower in those with type 2 diabetes than in those

with type 1 disease (11.14 versus 22.89 nmol/L, P<0.001), Paresh

Dandona, M.D., Ph.D., of the State University of New York at Buffalo,

and colleagues reported online in Diabetes Care.

Free testosterone concentrations were also significantly lower in men

with type 2 diabetes (0.296 versus 0.489 nmol/L, P<0.001); a third of

them were hypogonadal compared with 8% of the type 1 diabetics

(P=0.02).

Dr. Dandona and his colleagues had previously found lower

testosterone levels in middle-age men with type 2 diabetes.

" These new findings have several clinical implications besides the

impairment of sexual function in these young men, " Dr. Dandona said.

Low levels of testosterone may result in diminished bone mass, loss

of skeletal muscle, increased weight gain and greater insulin

resistance, and an elevated risk of atherosclerosis and heart disease

caused by higher concentrations of C reactive protein, Dr. Dandona

added.

The researchers measured serum testosterone levels in 38 men with

type 1 diabetes (mean age 26.45) and 24 with type 2 disease (mean age

27.87).

The type 2 diabetics were significantly more overweight (body mass

index 38.66 versus 27.41 kg/m2, P<0.001) -- 21 of 24 were obese.

The researchers compared the mean free testosterone level in the type

2 diabetics with the normal range found in a previous study of men

ages 20 to 29. On the basis of that comparison, the prevalence of

hypogonadism jumped from 33% to 58%.

In addition to low levels of testosterone, the type 2 diabetics had

inappropriately low concentrations of luteinizing hormone and

follicle stimulating hormone, according to the researchers. Patients

who had low levels of all three had hypogonadotropic hypogonadism.

" Whether obesity or insulin resistance is the major determinant of

hypogonadotrophic hypogonadism has to be addressed in future studies,

and the pathogenesis of [the condition] needs to be defined, " Dr.

Dandona said.

Overall, free testosterone concentrations were negatively associated

with age (P<0.01) and BMI (P<0.001).

Total testosterone levels were positively associated with luteinizing

hormone (P=0.036) and follicle stimulating hormone (P<0.001) in type

1 diabetics but not in those with type 2 disease.

Free testosterone concentrations were positively associated with

follicle stimulating hormone in type 1 diabetics only (P<0.01).

Levels of LH and FSH were related to each other in type 1 diabetics

only (P<0.01).

Among type 2 diabetics, Hispanics had lower free testosterone

concentrations than blacks (P<0.05), which was explained by the older

age of the Hispanic men.

Free testosterone levels were higher in blacks than whites (P<0.05),

a consequence of the lower BMI of the black men.

The researchers said that the findings have clinical importance

because low testosterone levels may contribute to diminished libido

and erectile dysfunction.

In addition, low levels in younger men may decrease bone mass, cause

skeletal muscle to be lost, and increase weight gain, resulting in

greater insulin resistance.

Infertility is a possible complication as well, they said, because

below-normal levels of follicle stimulating hormone may negatively

affect the development of seminiferous tubules and spermatogenesis.

" The treatment plans for such patients should include not only

testosterone therapy but also the consideration of gonadotropin

therapy in order to restore fertility, " the researchers said.

The study was supported by a grant from the NIH to Dr. Dandona. The

authors made no disclosures.

Primary source: Diabetes Care

Source reference:

Chandel A, et al " Testosterone concentrations in young patients with

diabetes mellitus " Diabetes Care 2008; DOI: 10.2337/dc08-0851.

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