Alkaline phosphatase (ALP)
DEAlkalische Phosphatase (ALP)
Alkaline phosphatase (ALP) is an enzyme that snips phosphate groups in an alkaline environment. The level in your blood is a mix of forms from several organs, mainly your liver, bone, intestine, and (in pregnancy) placenta. A high ALP most often means liver or bile-duct trouble (especially cholestasis) or fast bone turnover (as in Paget's disease, bone metastases, or overactive parathyroid). How do you tell liver from bone? If GGT (or 5'-nucleotidase) is up alongside ALP, the source is the liver, since bone-building cells do not make those. A low ALP can point to a rare condition (hypophosphatasia), zinc or magnesium deficiency, or low thyroid. In longevity terms, a persistently high ALP has been tied to higher death from all causes and from heart disease, even apart from liver disease.
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