Recategorisation of body mass index to achieve andrological predictive power: a study in more than 20 000 patients.

The aim of this study was to recategorise body mass index (BMI) in order to classify patients according to their risk of semen abnormalities. Patients (n=20563) presenting at an andrology laboratory were classified into five groups according to BMI: underweight (BMI <20kg m-2), normal weight (BMI 20-24.9kg m-2), overweight (BMI 25-29.9kg m-2), obese (BMI 30-39.9kg m-2) and morbidly obese (BMI >40kg m-2). Semen quality was evaluated to determine: (1) differences between groups using analysis of variance (ANOVA); (2) the chances of semen abnormalities (using generalised linear models, Chi-squared tests and odds ratios); (3) reference BMI values with andrological predictive power (multivariate conglomerate analyses and multivariate analysis of variance (MANOVA)); and (4) expected values of abnormalities for each new group resulting from BMI recategorisation. Morbidly obese and underweight patients exhibited the highest decrease in semen quality and had higher chances of semen abnormalities. The smallest number of sperm abnormalities was found at a BMI of 27kg m-2. Four reference values were identified, recategorising BMI into four groups according to their risk of semen abnormalities (from lowest to highest risk): Group1,BMI between 20 and 32kg m-2; Group2, BMI <20 and BMI >32-37kg m-2; Group3, BMI >37-42kg m-2; and Group4, BMI >42kg m-2. A BMI <20 or >32kg m-2 is negatively associated with semen quality; these negative associations on semen quality increase from a BMI >37kg m-2 and increase even further for BMI >42kg m-2. The BMI recategorisation in this study has andrological predictive power.

Effects of alcohol and cigarette consumption on human seminal quality.

OBJECTIVE: To evaluate the effects of alcohol or cigarette consumption on seminal parameters in a large population of men attending an andrology laboratory. DESIGN: Analysis of ten years of data (1990-1999). SETTING: Andrology and Reproduction Laboratory (Córdoba, Argentina). PATIENT(S): Patients (3,976) were grouped according to nonsmokers; <==20 cigarettes/day; >20 cigarettes/day; nonalcohol consumers; <==500 mL of wine ( approximately 52 g of ethanol) or equivalent/day; and >500 mL of wine or equivalent/day. Patients who drank alcohol and smoked were also considered. INTERVENTION(S): A questionnaire was voluntarily filled out by patients. It provided data on drug consumption and genitourinary diseases. MAIN OUTCOME MEASURE(S): Seminal volume, sperm concentration, motility, viability, and morphology. RESULTS: No statistical differences in seminal parameters were found between the degrees of alcohol or tobacco consumption; so, independently of the degree of consumption patients were considered as smokers or alcohol consumers. CONCLUSION(S): Alcohol or cigarette consumption did not alter the seminal parameters. Nevertheless, when the patients with these two habits were compared to those without these habits, a significant reduction in seminal volume, sperm concentration, percentage of motile spermatozoa, and a significant increase of the nonmotile viable gametes were detected. The synergic or additive effect of these two toxic habits is discussed.