I am 20. I have pigmentation around my lips, neck, stomach, back, hips and vulva. I also have a bit pigmented joints, like knees, elbows and knuckles. Could it be the prediabetes symptoms? Also, will my intimate area be lightened a bit if I lose weight (i'm overweight for my height) and maintain good diet. Further, i'll be doing intimate area skin care too. Thank you.