RESUMO
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.
Assuntos
Índice de Massa Corporal , Infertilidade Masculina/diagnóstico , Infertilidade Masculina/epidemiologia , Análise do Sêmen , Adolescente , Adulto , Argentina/epidemiologia , Astenozoospermia/epidemiologia , Humanos , Infertilidade Masculina/fisiopatologia , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Obesidade Mórbida/epidemiologia , Razão de Chances , Oligospermia/epidemiologia , Sobrepeso/epidemiologia , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Espermatozoides/anormalidades , Teratozoospermia/epidemiologia , Magreza/epidemiologiaRESUMO
En Chile, 10 a 15 por ciento de las parejas son consideradas como infértiles y el factor masculino es responsable en un 50 por ciento de los casos. El espermiograma, es un examen fundamental para el diagnóstico inicial de parejas infértiles. Objetivo: Determinar cambios en cuatro parámetros del espermiograma de mayor valor diagnóstico, según edad, estableciendo el parámetro alterado de mayor frecuencia. Métodos: Se realizo un estudio descriptivo retrospectivo de una muestra de 100 pacientes atendidos por problemas de fertilidad entre los años 2004 y 2009, clasificándolos en cuatro grupos etarios. Resultados: Al evaluar la concentración espermática, el 33 por ciento presenta: 5 baja concentración. El 86 por ciento de los pacientes presento astenozoospermia. El 81 por ciento de los pacientes presento anormalidad en la morfología espermática. La viabilidad espermática fue anormal en el 8 por ciento de los pacientes, siendo significativamente más alto en el grupo etario de mayor edad. Conclusiones: Los parámetros estudiados muestran un alto porcentaje de anormalidad en la población en estudio. Al comparar entre grupos, el grupo de mayor edad (sobre los 47 &los) presenta un aumento significativo del- porcentaje de alteraciones en morfología, motilidad y viabilidad respecto a los otros grupos etarios, estableciéndose la edad como un factor negativo en la calidad espermática. La movilidad corresponde al parámetro mas frecuentemente alterado seguido por la morfología espermática a medida que el varón consultante envejece.
In Chile, 10 to 15 percent of the couples are considered as infertile. Since the male factor is responsible of 50 percent of the cases, spermogram is an essential test for initial diagnosis of the infertile couple. Objective: To analyze the frequency of change in four spermogram parameters -according to age- to determine their diagnostic value. Method: A descriptive retrospective study of spermogram data from 100 patients -subdivided in four age groups- analyzed in our Unit for fertility problems between 2004 and 2009 was performed. Results: In sperm count, 33 percenr showed an abnormally low concentration. An 86 percent of the patients has astenozoospermia. 81 percent of the patients showed abnormal sperm morphology. Sperm viability was subnormal in 8 percent of the patients, being significantly higher in the oldest group. Conclusions: The seminal parameters analyzed revealed a high percentage of anomalies in the studied population. The oldest group had significant percentages of anomalies in sperm motility, morphology and viability, thus corroborating that age is a negative factor that affects semen quality. Sperm motility was the most frequently altered parameter followed by sperm morphology in the population under study.