Here’s another chicken or egg question: Do poor sleep habits cause diabetes and lower melatonin levels, or does diabetes cause lower levels of melatonin? In this study out of Brigham and Women’s Hospital in Boston, having lower levels of melatonin was associated with a higher risk of diabetes. This does not prove that having lower levels of melatonin will give you diabetes, but only an association where directionality is not known.
One minor detail that’s important to remember is that when darkness stimulates brain neurons to produce melatonin, the signals goes through the cervical sympathetic ganglion, before reaching the pineal gland. A common side effect from any of the high blood pressure medications is that it lowers function of this ganglion, which is involved in the sympathetic nervous system. Blood pressure medications can lower activity of your sympathetic nervous system, which can in theory lower your melatonin levels.
So of you have high blood pressure, by taking blood pressure medications, you could be lowering your melatonin levels, which lead to poor sleep, which can result in weight gain, which can aggravate snoring and obstructive sleep apnea….and we know that obstructive sleep apnea can raise your sugar levels.
This example only shows that the human body can’t be reduced to one single molecule or chemical at a time. We need to look at multiple aspects of our physiology simultaneously.