Friday, November 30, 2012

Kidney Function and Bone Mineral Density

Chronic Kidney Disease (CKD) is the progressive loss of renal function. It is most common among older people and those with high blood pressure and/or diabetes.  Early stages can be detected through routine lab tests. As kidneys slowly lose their ability to excrete waste products, urine protein and serum creatinine levels rise - and urine pH drops (Nakanishi et al., 2012). For the 10 to 15% of Americans experiencing CKD, the risk of bone fracture is significantly higher as well. 

Here’s the connection: 
In addition to the important functions of waste excretion and body pH regulation, healthy kidneys produce calcitriol (1,25(OH)2D), the active form of vitamin D that helps the body absorb dietary calcium into the blood and the bones. Even slight kidney impairment can slow this conversion of vitamin D to calcitriol. The less calcitriol in the blood, the less calcium will be absorbed from the food you eat or supplements you take. If calcium absorption drops, levels in the blood become too low. This low blood calcium is detected by sensors in four small parathyroid glands in the neck and triggers their release of a hormone called parathormone (PTH). This hormone draws calcium from the bones to raise blood calcium levels. Too much PTH in the blood (a condition called hyperparathyroidism) will remove excessive amounts of calcium from the bones. Over time, this constant removal of calcium will speed up the loss of bone mineral density (BMD) and increase the risk of bone fracture. Insuring adequate levels of vitamin D intake will help avoid this release of PTH but in individuals with CKD there still may be poor conversion to the active form of D.
There are a number of research studies underway to identify how to reduce or reverse the negative effects on bone for CKD patients.
 
In a study published in the American Journal of Clinical Nutrition researchers (Alvarez et al., 2012) explored whether high doses of vitamin D3 (cholecalciferol) in patients with early CKD (stages 2 and 3) was sufficient to maintain optimal vitamin D status (greater than 30 ng/ml) and to prevent the rise of blood PTH levels. Forty-six subjects were supplemented with 50,000 IU oral vitamin D3 each week for 12 weeks followed by 50,000 IU every other week for 40 weeks. After one year, the authors concluded that this "regime was safe and sufficient to maintain serum 25(OH)D [vitamin D] concentrations and prevent vitamin D insufficiency in early CKD. 

Furthermore, serum PTH improved after cholecalciferol treatment, particularly in patients who had secondary hyperparathyroidism." It appears that by flooding the body with high doses of vitamin D the kidneys are able to produce more active vitamin D. With more of this active form, signaling of the parathyroid glands to release more PTH is turned off.
 
In addition to the compromised ability to activate vitamin D and excrete wastes, as kidney function decreases in CKD patients demonstrate low-grade, chronic metabolic acidosis. Their low urine pH is a reflection of this acidotic state. Alkalinizing potassium* and magnesium supplementation are helpful for increasing body pH levels. Additionally, sources high in the amino acid glutamine (such as whey protein) that is used by the body to produce bicarbonate, the body's most important buffering compound, is helpful in neutralizing acidosis. 
If your kidney function is compromised, be sure to speak with your medical provider about this important aspect of your treatment.
* Note:  Excessive intake of potassium in patients with kidney disease can lead to hyperkalemia, a serious medical condition that can lead to abnormal heart rhythms. If you have kidney disease, consult with your physician before taking supplemental potassium. 
Nakanishi et al. 2012. Low urine pH is a predictor of chronic kidney disease. Kidney and Blood Pressure Research 35(2):77-81.
Alvarez et al. 2012. High-dose cholecalciferol reduces parathyroid hormone in patients with early chronic kidney disease: a pilot, randomized, double-blind, placebo-controlled trial. American Journal of Clinical Nutrition 96(3):672-679.

Wednesday, November 28, 2012

Labisia pumila (Kacip Fatimah): Is it Useful for Post-Menopausal Osteoporosis?

Since the Women's Health Initiative came to an abrupt halt 10 years ago with findings that hormone replacement therapy (HRT) increased the risk of heart attack, stroke, blood clots, and breast cancer, the search for alternative antiosteoporotic phytoestrogens has intensified. Flax seed, soy, red clover, and hops are some of the most researched phytoestrogens. But over the past several years an herb called Labisia pumila has been more aggressively examined for it's phytoestrogenic properties and possible role in the prevention and treatment of osteoporosis. Labisia pumila, commonly known as Kacip Fatimah, has been used for centuries in South East Asian countries (predominantly in Malaysia) to promote healthy sexual function, ease menstrual pain, induce labor, and recover from childbirth.

Here are some of the recent findings and conclusions by researchers concerning the possible role of Labisia pumila in the prevention and treatment of osteoporosis.

  • Supplementing rats for 8 weeks "was able to prevent the changes in bone biochemical markers [reduced CTX, a bone resorption marker] but failed to prevent the bone calcium loss induced by ovariectomy."    Shuid et al., 2011. The effects of Labisia pumila var. alata on bone markers and bone calcium in a rat model of post-menopausal osteoporosis. J Ethnopharmacol 133(2):538-542.
  • "...has the potential as an alternative to ERT for prevention of postmenopausal osteoporosis.Fathilah et al., 2012. Labisia pumila protects the bone of estrogen-deficient rat model: a histomorphometric study. J Ethnopharmacol 142(1):294-299.
  • "...has the potential to be used as an alternative treatment for postmenopausal osteoporosis. All in all, it is the anti-inflammatory, phytoestrogenic, and antioxidatve properties of LP [Labisia pumila] that make it an effective natural medicine in treatment and prevention of osteoporosis." Nadia et al., 2012. The anti-inflammatory, phytoestrogenic, and antioxidative role of Labisia pumila in prevention of postmenopausal osteoporosis. Advances in Pharmacological Sciences doi:10.1155/2012/706905.
  • "...has beneficial effect to reduce the triglyceride (TG) values. Thus, it may be a useful phytosupplement for maintaining cardiovascular health in menopausal women. However, there was no effect on the hormonal profiles." Kadir et al., The effect of Labisia pumila var. alata on postmenopausal women: a pilot study. Evidence-Based Complementary and Alternative Medicine doi:10.1155/2012/216525.
  • "...has the potential to prevent osteoporotic fractures in the postmenopausal or estrogen-deficient state. I may be taken as supplements by postmenopausal women who are afraid of the side effects of estrogen. [Labisia pumila] seemed to be safer than Premarin as it exhibited no reproductive toxicity in animal at forty-five times higher than the dose used in the present study."  Fathilah et al., 2012. Labisia pumila prevents complications of osteoporosis by increasing bone strength in a rat model of postmenopausal osteoporosis. Evidence-Based Complementary and Alternative Medicine doi:10.1155/2012/948080.

Although many people assume natural alternative medicines such as Labisia pumila to be safe, there have actually been no long-term human safety studies with this herb. That said, the fact that Labisa pumila has been used for centuries to treat disease with no documented adverse effects, its use in the treatment of post-menopausal osteoporosis appears promising.

Tuesday, November 27, 2012

Tune in to Dr. Paul Christo's Radio Show--Aches and Gains

This coming Saturday evening (December 1 at 9 pm EST) I'll be a guest on Dr. Paul Christo's radio show, Aches and Gains (WBAL 1090 AM). Dr. Christo, a Harvard-trained anesthesiologist and John Hopkin's trained pain medicine specialist, is one of America's foremost experts on relieving pain. With chronic residual pain often a consequence of osteoporosis-related fractures, Dr. Christo and I will have a lot to talk about. Tune in if you can.
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