From the Guidelines
Elevated alkaline phosphatase (ALP) with normal isoenzyme levels in a geriatric female is most likely due to bone-related causes rather than liver disease, with Paget's disease of bone being a common explanation. The most recent and highest quality study 1 suggests that pathologically increased levels of ALP may occur in bone disease, such as Paget’s disease, bony metastases, or fracture. Other potential causes include osteomalacia, recent fractures, bone metastases, or certain medications like phenytoin. In elderly women, osteoporosis with increased bone turnover can also contribute to elevated ALP.
Some key points to consider in the diagnosis and management of elevated ALP in a geriatric female include:
- Bone-specific ALP testing to confirm the source of the elevation
- Vitamin D levels and parathyroid hormone measurement to assess for underlying bone disease
- Bone imaging studies to evaluate for fractures, osteomalacia, or other bone abnormalities
- A thorough medical history to identify potential causes of elevated ALP, such as medications or underlying medical conditions
The chronic nature of the elevation suggests an ongoing process rather than an acute condition. Treatment depends on the underlying cause - for Paget's disease, bisphosphonates like alendronate or risedronate are typically prescribed, while vitamin D supplementation would be appropriate for osteomalacia. The elevation being twice the upper limit suggests significant bone turnover but is not necessarily indicative of severe disease. According to the study 2, measurements of GGT can indicate whether pathologically elevated ALP is of hepatic or nonhepatic origin, and concomitantly elevated GGT can help confirm that an elevated ALP originates from the liver and indicates cholestasis. However, in this case, the normal isoenzyme levels suggest a bone-related cause rather than liver disease.
From the Research
Possible Causes of Elevated Alkaline Phosphatase
- Elevated alkaline phosphatase (ALP) levels can be caused by various factors, including liver disease, bone disorders, and certain medications 3, 4.
- In the case of a geriatric female with chronic elevation of ALP, it is possible that the cause is related to liver or bone disease, or a combination of both.
- The fact that the isoenzyme levels are normal suggests that the elevation in ALP is not due to bone-related disorders, but rather liver-related disorders or other factors.
Role of Antiepileptic Drugs
- Antiepileptic drugs have been shown to induce liver microsomal enzymes, including liver ALP, which can lead to elevated ALP levels 3.
- This could be a possible cause of the chronic elevation in ALP levels in the geriatric female, especially if she is taking antiepileptic medications.
Vitamin D Deficiency
- Vitamin D deficiency has been linked to elevated ALP levels, particularly in patients with chronic kidney disease or those taking antiepileptic medications 4, 5.
- It is possible that the geriatric female has a vitamin D deficiency, which could be contributing to the elevated ALP levels.