Figure 6: Age distribution of the number of activated sweat glands and trend lines obtained by linear regression analyses. •=male (n = 64), ○=female (n = 37). In both graphs, the trend lines for male data are shown by solid lines and trend lines for female data are shown by dashed lines. The equations and coefficient of determination (R2) for males and females are shown above and below the lines. (a) In both male and female data, the number of sweat glands on the body surface according to age was found to have a low R2, which means that it was virtually independent of age. Even in males, the number increased with age. (b) The number of sweat glands on the forearms also did not show enough R2 to indicate a statistically significant relationship with age in either males or females, only showing a tendency to decrease.