Obese patients are more sensitive to pressure pain than those who are not overweight, and are equally susceptible to extremes of hot and cold, according to UK researchers.
A small study by Leeds Beckett University has highlighted the differences in pain response between different groups of people.
“Obese people are more susceptible to pressure pain”
The study authors said their results indicated the need for weight loss programmes to be part of pain management plans for obese patients experiencing chronic pain.
The team investigated 74 volunteers who were categorised, according to body mass index, as obese, overweight or normal.
Each group had pressure, cold and heat applied to two different areas of the body. The first experiment tested the hand at the base of the thumb – an area with little body fat.
The second measured responses near the waist, in an area where extra fat is stored. Volunteers were asked to report at what point the pressure, cold or heat first felt painful.
Each volunteer was also asked to report their experience of cold pain by putting their hands into icy water. Again, they were asked to report the point at which they felt pain.
Obese volunteers reported feeling pain from pressures equivalent to around 4.3kg per square centimetre, compared to about 8.6kg per square centimetre for those in the “normal” group.
Interestingly, the middle group, those classed as “overweight”, had a slightly higher pressure pain threshold than the normal group, with pain being reported at 10kg per square centimetre.
In terms of response to hot and cold temperatures, there was no significant difference across any of the groups, when tested at the waist, said the researchers in the European Journal of Pain.
Only a small increase in sensitivity was reported in tests on the hand, suggesting that an extra layer of fat was no protection against extreme temperatures.
Study author Dr Osama Tashani, senior research fellow at the Centre for Pain Research at Leeds Beckett, said. “Obese people are more likely to experience pain from factors such as the mechanical impact of increased weight on joints than people with a normal BMI.
Pain management plans ‘should include weight loss’
“But our study suggests that even in areas of the body which are not bearing weight, obese people are more susceptible to pressure pain,” he added.
“The overweight group had the highest pressure pain threshold, which might be because there were more people in this group taking part in physical activities, which could also affect how a person feels pain,” said Dr Tashani.
However, he noted that, while obese people were likely to have the lowest pressure pain threshold, it could be that those with a low pressure pain threshold were more likely to become obese.
“It could be the case that a person who is more sensitive to pain is less likely to do physical activity and therefore more likely to gain weight and become obese,” said Dr Tashani.