Handedness and sleep apnea

Lateralization of Squamous Cell Carcinomas in the Head-Neck Region

Earlier studies have shown the lateralization of several immune disorders, including herpes zoster infection and breast cancer. We investigated whether there is lateralization of squamous cell carcinomas in the head-neck region and a relation of handedness with this cancer. Analysis showed right-sided lateralization of head-heck cancers in right-handed patients and vice versa in left-handed ones and a higher rate of left-handedness in patients with squamous cell cancer. Associations among left-handedness, squamous cell carcinoma, and its lateralization may result from a genetic togetherness.

Handedness Correlates with Actigraphically Measured Sleep in a Controlled Environment

The relationship between hand preference and duration of sleep was assessed in 40 healthy subjects using self-report estimates, sleep diaries, and wrist activity monitors during an uncontrolled 7-day at-home phase and during a controlled overnight stay in a sleep laboratory. Handedness was unrelated to any index of sleep duration when assessed in the unregulated home environment. In the controlled environment of the laboratory, however, greater right-hand dominance was positively correlated with more minutes of obtained sleep and greater sleep efficiency. Findings were consistent with previous reports which suggest measures of brain lateralization may be related to sleep and health but further suggest that these relationships may be easily obscured by extraneous environmental factors when assessed in an uncontrolled setting.

The epidemiology of left-handedness in a hospital population

PURPOSE

We evaluated the association between left-handedness (LH) and age, education, cigarette smoking, alcohol consumption, and disease status in a case-control study of 8801 hospitalized patients with cancer and those with other conditions.

METHODS

Subjects were interviewed in person using a structured questionnaire that contained detailed sections of lifestyle behaviors.

RESULTS

The overall prevalences of LH were 7.6% among men and 6.5% among women. Among both sexes LH declined with increasing age (P < 0.05). After adjustment for age, the following associations were observed. Men had a higher risk of LH than women. The prevalence of LH was lower in ever-married subjects compared with never-married subjects (odds ratio [OR] for men, 0.7; 95% confidence intervals [CI], 0.5-0.9; for women, OR, 0.5; 95% CI, 0.3-0.9). Among men, the prevalence of LH was not associated with race, years of education, smoking status, or levels of alcohol consumption. The risk of LH was elevated in men diagnosed with fractures as compared with all other male patients (OR, 2.4; 95% CI, 1.3-6.7). Among women, LH was not associated with race, smoking, or hormonal and reproductive factors, but LH was more common among female high-school and college graduates and among self-reported alcoholics. The odds ratio of LH was significantly lower in women with breast cancer (OR, 0.3; 95% CI, 0.1-0.7).

CONCLUSIONS

The increased risk of serious injuries in LH is not a result of higher alcohol use. Handedness might be an important factor in the safe use of industrial equipment.