Is there a way(s) to reduce necks-size(probable result of exercising or heredity) which is causing obstructive sleep apnea?

Loose weight : Loosing 15 pounds or do will help. But a visit with EnT will help rule out other areas of obstruction

Of course: Patients who are overweight often have bulky and excess tissues in their throat which can make snoring and apnea worse. Your physician can help you develop a plan to lose weight and keep it off.

Eat less: Weight loss significantly decreases risk of OSA.