Effect of hormonal supplementation on pain tolerance in women– A comparative study

Abstract

Gonadal hormones (oestrogen and progesterone) influences pain sensitivity, the former strongly influences nociceptive actions, whereas the latter prevents neuropathic pain. However, there is only little evidence on direct effect of hormonal based drugs on experimental pain response. Therefore the aim of the present study is to the difference in response to pain stimulus in terms of - pain threshold, pain tolerance, pain intensity, pain unpleasantness between women on OCP pills, normal menstruating women and age matched men using cold pressor test.Total of 50 females (20-35 years age group) on COCP pills, 50 controls (normal menstruating women of 20-35 years age group) and 50 healthy males (20-35 years age group) were enrolled in the study as per the eligibility criteria. Cold pressor test was used as a stimulus source. The participants were instructed to hold their least dominant hand in the water bath (maintained between between 0°C and 2°C) as long as possible and were requested to inform the first sensation of pain which denoted the participants’ pain threshold. Time from pain threshold to the point where participants could no longer cope with pain and indicate stop, was recorded as pain tolerance. At this point participants were directed to note pain intensity and unpleasantness on the visual analogue scale.Statistical analysis of data was done using standard SPSS software. Data was represented as mean standard deviation. Chi-square test was done and p values <0.05 were considered significant. Average pain tolerance was significantly (p<0.00) higher in women on COCP (combined oral contraceptive pill) therapy compared to naturally menstruating women. But men and women on COCP pill therapy do not differ significantly in average pain tolerance. The average pain threshold did not differ significantly between any age groups. The average pain unpleasantness was less in females taking hormonal pills compared to men and naturally menstruating women establishing the role of increased levels of sex hormones in reducing the discomfort and unpleasantness. There was no significant difference in average pain intensity between men and normal women but it differed significantly between normal women and women on COCP therapy.The use of COCP affects the pain reporting of subjects.