Earlier Sex, More Lifetime Partners in US MSM Than in Heterosexuals

US men who have sex with men (MSM) start having sex earlier than heterosexual men and women, and they meet more new sex partners throughout their 20s and 30s, according to results of several large telephone surveys in the United States.

Both biological and behavioral factors lie behind the higher risk of HIV infection and other sexually transmitted infections in MSM than in heterosexuals in the United States and some other countries with similar HIV epidemics. To examine sexual behavioral differences between MSM and heterosexuals more closely, researchers planned this comparison.

The investigators studied MSM and male and female heterosexuals from 18 to 39 years old using four population-based random-digit telephone dialing surveys. MSM was assessed in a 1996-1998 survey in 4 US cities and in Seattle, Washington surveys in 2003 and 2006. Data on heterosexuals came from a 2003-2004 Seattle survey.

Compared with heterosexuals, MSM began having sex at a younger age. MSM met new sex partners for a longer time throughout life than did heterosexuals, and MSM stopped forming new partnerships at a more gradual pace than heterosexuals.

Higher proportions of MSM than heterosexual men or women formed new sex partnerships during their 20s and 30s:

Percent forming new partnership in past year among 18- to 24-year-olds:
• MSM: 86%
• Heterosexual men: 56%
• Heterosexual women: 21%

Percent forming new partnership in past year among 35- to 39-year-olds:
• MSM: 72%
• Heterosexual men: 34%
• Heterosexual women: 10%

Compared with heterosexuals, MSM were more likely to choose partners more than 5 years older. And MSM were 2 to 3 times more likely than heterosexuals to have recent concurrent partnerships.

MSM reported more consistent condom use during anal sex than heterosexuals reported during vaginal sex.

The researchers believe their findings “likely help to explain higher HIV/sexually transmitted infections rates among MSM, despite higher levels of condom use.”

Source: Sara Nelson Glick, Martina Morris, Betsy Foxman, Sevgi O. Aral, Lisa E. Manhart, King K. Holmes, Matthew R. Golden. A comparison of sexual behavior patterns among men who have sex with men and heterosexual men and women. JAIDS. 2012; 60: 83-90.

For the study abstract

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Written by Mark Mascolini on behalf of the International AIDS Society