Dehydroepiandrosterone sulfate (DHEA-S) levels above 700–800 µg/dL are highly suggestive of adrenal dysfunction because DHEA-S is made exclusively by the adrenal glands. The free testosterone level is thought to be the best measure, with approximately 60 per cent of PCOS patients demonstrating supranormal levels.Some other blood tests are suggestive but not diagnostic. The ratio of LH (Luteinizing hormone) to FSH (Follicle-stimulating hormone), when measured in international units, is elevated in women with PCOS. Common cut-offs to designate abnormally high LH/FSH ratios are 2:1 or 3:1 as tested on Day 3 of the menstrual cycle. The pattern is not very sensitive; a ratio of 2:1 or higher was present in less than 50% of women with PCOS in one study. There are often low levels of sex hormone-binding globulin, in particular among obese or overweight women.Anti-Müllerian hormone (AMH) is increased in PCOS, and may become part of its diagnostic criteria. Glucose tolerance testing
2-hour oral glucose tolerance test (GTT) in women with risk factors (obesity, family history, history of gestational diabetes) may indicate impaired glucose tolerance (insulin resistance) in 15–33% of women with PCOS. Frank diabetes can be seen in 65–68% of women with this condition. Insulin resistance can be observed in both normal weight and overweight people, although it is more common in the latter (and in those matching the stricter NIH criteria for diagnosis); 50–80% of people with PCOS may have insulin resistance at some level. Fasting insulin level or GTT with insulin levels (also called IGTT).
Hereditary fructose intolerance (HFI) is an inborn error of fructose metabolism caused by a deficiency of the enzyme aldolase B. Individuals affected with HFI are asymptomatic until they ingest fructose, sucrose, or sorbitol. If fructose is ingested, the enzymatic block at aldolase B causes an accumulation of fructose-1-phosphate which, over time, results in the death of liver cells. This accumulation has downstream effects on gluconeogenesis and regeneration of adenosine triphosphate (ATP). Symptoms of HFI include vomiting, convulsions, irritability, poor feeding as a baby, hypoglycemia, jaundice, hemorrhage, hepatomegaly, hyperuricemia and potentially kidney failure. While HFI is not clinically a devastating condition, there are reported deaths in infants and children as a result of the metabolic consequences of HFI. Death in HFI is always associated with problems in diagnosis.HFI is an autosomal recessive condition caused by mutations in the ALDOB gene, located at 9q31.1. HFI is typically suspected based on dietary history, especially in infants who become symptomatic after breast feeding. This suspicion is typically confirmed by molecular analysis Treatment of HFI involves strict avoidance of fructose in the diet. Older patients with HFI typically self-select a diet low in fructose, even before being diagnosed. Presentation
The key identifying feature of HFI is the appearance of symptoms with the introduction of fructose to the diet. Affected individuals are asymptomatic and healthy, provided they do not ingest foods containing fructose or any of its common precursors, sucrose and sorbitol. In the past, infants often became symptomatic when they were introduced to formulas that were sweetened with fructose or sucrose.