A recent study published in the journal PLOS ONE evaluated the association between sexual interest and mortality.
Sexual interest is essential for positive sexual function and relationships, which have been recognized as good quality of life and health indicators. One study reported an association between sexual activity and positive psychologic factors. Prior studies indicate that positive psychologic factors decrease the risk of cancer and cardiovascular disease and enhance longevity.
In contrast, negative psychologic factors are associated with higher mortality risk. Research interest in sexuality in older adults has been significantly growing lately. Still, how sexuality is related to longevity is poorly understood. Previous studies reported gender differences in the impact of psychological factors on longevity, with a more substantial effect on all-cause death among males than females.
Study: Association between lack of sexual interest and all-cause mortality in a Japanese general population: The Yamagata prospective observational study. Image Credit: VGstockstudio / Shutterstock
About the study
The present study investigated the association between the lack of sexual interest and mortality in Japan. Individuals at an annual health check who were aged 40 or older were enrolled from 2009 to 2015. Subjects were followed up to nine years and assessed for associations with all-cause, cardiovascular, and cancer mortalities.
At baseline, questionnaires were used to obtain information on participants’ medical history, current symptoms or medications, blood pressure, sexual interest, laughter frequency, smoking status, marital status, physical activity, alcohol intake, education level, social involvement, and perceived mental stress.
Sexual interest was determined by asking participants if they were interested in individuals of the opposite sex. Sexual interest in same-sex individuals was not considered in this analysis. The frequency of laughing out loud was examined, and the responses were categorized as ≥ 1 per week, ≥ 1 per month but ≤ 1 per week, and ≤ 1 per month.
Alcohol intake was stratified as current, past, and non-drinker; smoking status was similarly stratified. Subjects were asked about their participation frequency in social groups and civic associations, with responses grouped into the same three categories as laughter frequency. Psychologic distress was assessed using the Kessler psychologic distress scale (K6). Participants indicated their current or past history of depression.
The location and date of death were confirmed from death code certificates. Analysis of variance (ANOVA) and chi-squared tests were used for differences in mean values and proportions, respectively. Kaplan-Meier analysis with log-rank test and Cox proportional hazards analysis were used to compute associations between the lack of sexual interest and mortality variables.
The researchers enrolled 19,054 subjects, including 11,386 females and 7,668 males, for the analysis, who were followed up for a median of 7.1 years. The average age was 64.2 in males and 61.6 in females. Lack of sexual interest was reported by 8.3% of males and 16.1% of females. The proportions of current smokers, past drinkers, and psychologically distressed individuals were significantly higher among participants lacking sexual interest.
Moreover, subjects lacking sexual interest showed lower laughter frequency and were less educated. The diabetes rate was higher among males without sexual interest than those with sexual interest. During the follow-up period, 503 deaths were recorded, including 162 due to cancer and 67 due to cardiovascular disease. In the unadjusted Cox proportional hazards model, all-cause and cancer mortalities were significantly higher among males lacking sexual interest.
The risk for all-cause mortality was significantly higher among males lacking sexual interest after adjusting for age, education, diabetes, smoking status, alcohol intake, hypertension, marital status, education, body mass index, laughter frequency, dyslipidemia, and psychological distress. Furthermore, lack of sexual interest was significantly associated with a higher risk for cancer mortality among males after adjusting for age.
In summary, the researchers observed that 8.3% of males and 16.1% of females in a sample of over 19,000 Japanese people lacked sexual interest. Furthermore, negative psychologic factors were associated with the lack of sexual interest in both genders. Notably, lacking sexual interest was associated with all-cause death among males after adjusting for established risk factors.
Notwithstanding, some confounding factors may have been unidentified. Moreover, the team did not adjust for neurologic conditions, medications, and depression due to the absence of relevant data at baseline. Above all, the findings suggest that the lack of sexual interest is a risk factor for all-cause death in males but not in females and that sexual interest might improve longevity in males.