Prevalence of night sweats in primary care patients: an OKPRN and TAFP-Net collaborative study - Original Research - Statistical Data Included

Journal of Family Practice, May, 2002 by James W. Mold, Migi K. Mathew, Shuaib Belgore, Mark DeHaven

Frequency of reporting of night sweats

A minority of patients with night sweats (12%) had reported the symptom to their physicians. This was true even for those with severe night sweats (46%). Women younger than 70 years were more likely than men of the same age to have reported their night sweats to their physicians (15% vs. 6%; P < .001). The reverse was true for those 70 years and older (7% vs 13%; P =.08). Older patients with pure night sweats were more likely than younger patients to have reported them. After controlling for other variables, patients who were older (odds ratio [OR] = 1.03 per year of age; P < .001), those with night and day sweats (OR = 1.74; P =.0015), and those who reported that their night sweats bothered others (OR = 2.89; P =.001) were more likely to have reported the symptom to their physicians. Those who had reported their night sweats were also more likely to have hot flashes (OR = 2.98; P < .001) and to take estrogen (OR = 1.72; P =.003).

Factors associated with night sweats

The only variable associated with pure night sweats after controlling for all other variables was panic attacks. Variables associated with night and day sweats were younger age, greater body mass index, hot flashes, chronic infection, sleep disturbances, selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, "other" (non-SSRI, non-tricyclic) antidepressants, and xanthines.

For women, the only variable clearly associated with pure night sweats in the multivariate model was hot flashes. Panic attacks nearly reached significance (P =.026) and improved the regression model substantially (deviance reduced from 1446 to 87). Variables associated with night and day sweats were weight, sleep problems, hot flashes, antihistamines, SSRIs, and other (non-SSRI, non-tricyclic) antidepressants.

For men, the only variable associated with pure night sweats after controlling for other variables was sleep problems. After exclusion of sleep problems and sedatives from the model on the assumption that they might be the result rather than the cause of night sweats, significant predictors were hot flashes (OR = 2.70; 95% confidence interval [CI], 1.35-5.40; P =.005) and regular use of multivitamins (OR = 1.87; 95% CI, 1.17-2.99; P =.009). Variables associated with night and day sweats included greater weight, hot flashes, and greater alcohol use. The ORs and CIs are shown in Table 1.

Interestingly, 32 men (5%) reported hot flashes, and those who did were more likely to report night sweats of both types. Men with hot flashes were evenly distributed across age categories. Their night sweats were more frequent, but not more severe, and they were more likely to bother others than those without hot flashes. Men with hot flashes were more likely to have told their physicians about their night sweats. After controlling for other variables, men with hot flashes were much more likely to have panic attacks (OR = 28.28; P < .001).

Patients 70 years and older made up 19.5% of our sample (N=429). The only factor associated with pure night sweats in the multivariate model was sleep disturbances (OR = 2.04; = 95% CI, 1.21-3.42; P =.007). Exclusion of sleep disturbances left no associated variables. Variables associated with night and day sweats were hot flashes (OR = 15.14; = 95% CI, 6.43-35.68; P < .001) and corticosteroids (OR = 5.45; 95% CI 1.58-18.86; P =.007).