High number of sexual partners increases risk of chronic disease

Although previous studies have linked a high number of sexual partners with an increased risk of sexually transmitted infections, new research indicates that a high number of partners may also be associated with an increased risk of chronic disease. 

Methods
The study, published in BMJ Sexual & Reproductive Health, used cross-sectional data from the English Longitudinal Study of Ageing (ELSA), which was a population-representative longitudinal study of men and women aged ≥ 50 years living in England. ELSA participants were asked about their number of sexual partners via the Sexual Relationships and Activities Questionnaire (SRA-Q), which was administered as a self-completion measure. Participants were asked to indicate the number of sexual partners (vaginal/oral/anal sex) they had had in their lifetime. Based on their responses, participants were classified into one of four categories: 0-1, 2-4, 5-9, and ≥ 10 sexual partners).

Participants were also asked to assess their health using a single question, “Would you say your health is poor/fair/good/very good/excellent?” The authors focused on those who rated their health as fair/poor. Participants were also asked two questions regarding long-standing illness: (i) “Do you have any long-standing illness, disability, or infirmity? By long-standing, I mean anything that has troubled you over a period of time or that is likely to affect you over a period of time.” If yes, (ii) “Does this illness or disability limit your activities in any way?” Demographic information collected included age, ethnicity (white vs non-white), and partnership status. Socioeconomic status was determined from household non-pension wealth.

Findings
This study included a final sample for analysis of 2537 men and 3185 women (n = 5722). The mean age of participants was 64.25 (SD 9.75) years in men and 65.34 (SD 10.06) years in women. The majority of participants were married or cohabiting (73.6% of men, 60.6% of women), white (93.7% of men, 96.0% of women) non-smokers (85.5% of men, 86.9% of women), drank alcohol regularly or frequently (84.0% of men, 69.9% of women) and were moderately or vigorously active at least once a week (80.2% of men, 74.8% of women).

Among women, 40.8% reported having had 0-1 sexual partner in their lifetime, 35.5% had between 2 and 4 partners, 15.8% had between 5 and 9 partners, and 7.8% had 10 or more partners. Among men, the respective numbers were 28.5% (0-1), 29.0% (2-4), 20.2% (5-9), and 22.2% (≥10). In both men and women, a higher number of sexual partners was associated with younger age, being unmarried, and a high variance in wealth (highest or lowest quintile of wealth). Those with a higher number of sexual partners were more likely to report smoking, frequent alcohol intake and engaging in physical activity on a weekly basis. There was an association between higher number of sexual partners and white ethnicity in women, but not in men. On the other hand, there was an association between higher number of sexual partners and a greater number of depressive symptoms in men but not in women. 

Among women there was a statistically significant association between number of sexual partners and risk of limiting long-standing illness. Women who reported having had between 5 and 9 sexual partners had 64% higher odds of reporting a limiting long-standing illness compared to women who reported 0-1 sexual partners (OR 1.64, 95% CI 1.15-2.05, p= 0.003) and 64% higher for those how had 10 or more partners (OR 1.64, 95% CI 1.15-2.35, p= 0.007). Women who had 10 or more sexual partners in their lifetime also had 91% higher odds of reporting a diagnosis of cancer than those who had had 0-1 partners (OR 1.91, 95% CI 1.04-3.51, p= 0.038).

Conclusions
The authors believe their findings indicate that the number of lifetime sexual partners is associated with adverse health outcomes in a sample of older British adults. In women, there was also a statistically significant positive association between the number of sexual partners and the risk of limiting long-standing illness. The authors suggest that a patient’s sexual history could be used as a tool to assess cancer risk. However, more research is necessary to determine whether a causal relationship exists.