Arachidonic acid (with its precursor – linoleic acid) serve as a substrate to the production of inflammatory mediators known as eicosanoids, whereas the arachidonic acid-containing compound diacylglycerol (DAG) is a precursor to the endocannabinoid 2-arachidonoylglycerol (2-AG) while fatty acid amide hydrolase (FAAH) mediates the metabolism of anandamide into arachidonic acid.[37][35] Anandamide can also be produced from N-acylphosphatidylethanolamine via several pathways.[35] Anandamide and 2-AG can also be hydrolized into arachidonic acid, potentially leading to increased eicosanoid synthesis.[35] Metabolic syndrome is a risk factor for neurological disorders.[38] Metabolomic studies suggest an excess of organic acids, impaired lipid oxidation byproducts, essential fatty acids and essential amino acids in the blood serum of affected patients.
A positive result, in the absence of unequivocal high blood sugar, should be confirmed by a repeat of any of the above methods on a different day. It is preferable to measure a fasting glucose level because of the ease of measurement and the considerable time commitment of formal glucose tolerance testing, which takes two hours to complete and offers no prognostic advantage over the fasting test.[66] According to the current definition, two fasting glucose measurements above 7.0 mmol/l (126 mg/dl) is considered diagnostic for diabetes mellitus.
Cataracts and glaucoma are also more common among diabetics. It is also important to note that since the lens of the eye lets water through, if blood sugar concentrations vary a lot, the lens of the eye will shrink and swell with fluid accordingly. As a result, blurry vision is very common in poorly controlled diabetes. Patients are usually discouraged from getting a new eyeglass prescription until their blood sugar is controlled. This allows for a more accurate assessment of what kind of glasses prescription is required.