Osteoporosis, Sarcopenia
Conditions
Keywords
bone turnover, calcium excretion, nitrogen excretion, potassium bicarbonate, muscle loss, muscle atrophy, bone loss
Brief summary
There is increasing evidence that the acid-base balance of diet plays an important role in the health of bones and muscles. An excess of acid in the body can result in calcium loss and muscle breakdown. Potassium bicarbonate, a base supplement, can neutralize acid within the body. The purpose of this study is to determine the effectiveness of potassium and bicarbonate, alone and combined, at reducing bone loss and preventing muscle wasting in older adults.
Detailed description
The typical American diet of dairy products, grains, and meats results in excess acid build-up in the body. The kidney is often unable to remove this excess acid quickly enough, resulting in mildly elevated blood acidity. In an attempt to neutralize the acidity, the body releases calcium from its bones. Over time, however, this calcium loss can lead to decreased bone density and possibly osteoporosis. Excess acid in the body also stimulates the breakdown of muscle. The combination of osteoporosis and reduced muscle strength sets the stage for falls, fractures, and ultimately functional decline. At least 30% of older adults fall once a year and, of those falls, 5% result in fractures. Preserving muscle mass and strength is an effective way to lower the risk of falling and to maintain independence among older people. Potassium bicarbonate is a base supplement that can neutralize acid. The purpose of this study is to determine the effectiveness of potassium and bicarbonate, alone and combined, at reducing bone loss and preventing muscle wasting in older adults. This study will last 3 months. Participants will be randomly assigned to one of four treatment groups: * Group 1 will receive potassium bicarbonate supplements * Group 2 will receive potassium chloride supplements * Group 3 will receive sodium bicarbonate supplements * Group 4 will receive placebo supplements All participants will take three pills of their assigned supplement after each meal; this will occur on a daily basis throughout the study. Participants will also take a multivitamin and a 600-mg calcium tablet daily. Participants will not be required to alter their usual diet in any way, but they will be requested to not take their usual calcium and vitamin D supplements during the study. Study visits will occur on Days 1, 21, 49, and 84. Days 1 and 84 study visits will include a review of medical history and physical activity, blood collection, and evaluation of weight, blood pressure, calcium absorption, and muscle function. Collection of both a 24-hour urine sample and a calendar depicting compliance with the supplement schedule will also occur at these two visits. The other study visits, on Days 21 and 49, may include blood collection, calendar compliance checking, and weight and blood pressure measurements. Supplements will be handed out on Days 1, 21, and 49.
Interventions
DIETARY_SUPPLEMENTPotassium Bicarbonate
67.5 mmol/d given as three tablets after each meal, with a full glass of water
DIETARY_SUPPLEMENTSodium Bicarbonate
67.5 mmol/d given as three tablets after each meal, with a full glass of water
DIETARY_SUPPLEMENTPotassium Chloride
67.5 mmol/d given as three tablets after each meal, with a full glass of water
DIETARY_SUPPLEMENTplacebo (microcrystalline cellulose)
Given as three tablets after each meal, with a full glass of water
Sponsors
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Tufts University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Body mass idex less than 35 * Not currently on a weight gain or weight loss diet * Willing to maintain usual level of physical activity * Willing to refrain from taking own calcium supplements, antacids, or salt substitutes
Exclusion criteria
* Vegetarian * Use of glucocorticoids for more than 10 days in the 3 months prior to study entry * Use of estrogen, raloxifene, or calcitonin in the 6 months prior to study entry * Use of bisphosphonate or teriparatide in the 2 years prior to study entry * Current use of diuretics, nonsteroidal anti-inflammatory drugs (NSAIDS), beta-blockers, anabolic drugs (steroids or other), angiotensin converting enzyme (ACE) inhibitors, or angiotensin receptor blockers (ARBs) * Renal disease, including kidney stones in the 5 years prior to study entry or creatinine clearance less than 50 ml/min/1.73 m2 of body surface area * Hyperparathyroidism * Untreated thyroid disease * Significant immune disorder * Current unstable heart disease * Active malignancy or cancer therapy in the year prior to study entry * 24-hour urine calcium levels greater than 300 mg/d after 1 week of being off calcium supplements * Hypertension, congestive heart failure, arrythmias, or myocardial infarction in the 12 months prior to study entry * On a salt-restricted diet * Bone density total hip T score of less than -2.5 * Abnormal serum calcium * Alkaline phosphatase levels greater than 10% above the upper end of the reference range * Adrenal insufficiency, primary aldosteronism, or Bartter's syndrome * Diabetes mellitus * Alcohol use exceeding two drinks/day * Peptic ulcers or esophageal stricture * Screening serum 25(OH)D levels below 16 ng/ml
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Biochemical Markers of Bone Turnover | 3 month change in 24-hr urine values | Change in 24-hr urinary N-telopeptide/creatinine measured at baseline and 3 months |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Potassium Bicarbonate Participants will receive potassium bicarbonate in dosage of 67.5 mmol/d. This compound has no other name.
Potassium Bicarbonate: 67.5 mmol/d given as three tablets after each meal, with a full glass of water | 43 |
| Sodium Bicarbonate Participants will receive sodium bicarbonate in dosage of 67.5 mmol/d. This compound has no other name.
Sodium Bicarbonate: 67.5 mmol/d given as three tablets after each meal, with a full glass of water | 43 |
| Potassium Chloride Participants will receive potassium chloride in dosage of 67.5 mmol/d. This compound has no other name.
Potassium Chloride: 67.5 mmol/d given as three tablets after each meal, with a full glass of water | 42 |
| Microcrystalline Cellulose Participants will receive placebo is microcrystalline cellulose. This compound has no other name.
placebo (microcrystalline cellulose): Given as three tablets after each meal, with a full glass of water | 43 |
| Total | 171 |
Baseline characteristics
| Characteristic | Sodium Bicarbonate | Potassium Chloride | Microcrystalline Cellulose | Total | Potassium Bicarbonate |
|---|---|---|---|---|---|
| Age, Customized participant age | 62.6 years STANDARD_DEVIATION 7.6 | 63.4 years STANDARD_DEVIATION 7.7 | 63.3 years STANDARD_DEVIATION 7.7 | 62.9 years STANDARD_DEVIATION 7.7 | 62.2 years STANDARD_DEVIATION 7.6 |
| Race and Ethnicity Not Collected | — | — | — | 0 Participants | — |
| Region of Enrollment United States | 43 participants | 42 participants | 43 participants | 171 participants | 43 participants |
| Sex: Female, Male Female | 24 Participants | 24 Participants | 25 Participants | 97 Participants | 24 Participants |
| Sex: Female, Male Male | 19 Participants | 18 Participants | 18 Participants | 74 Participants | 19 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 1 / 43 | 3 / 43 | 7 / 42 | 1 / 43 |
| serious Total, serious adverse events | 0 / 43 | 0 / 43 | 0 / 42 | 0 / 43 |
Outcome results
Primary
Biochemical Markers of Bone Turnover
Change in 24-hr urinary N-telopeptide/creatinine measured at baseline and 3 months
Time frame: 3 month change in 24-hr urine values
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Potassium Bicarbonate | Biochemical Markers of Bone Turnover | -6.25 nmol/mmol | Standard Error 1.75 |
| Sodium Bicarbonate | Biochemical Markers of Bone Turnover | -3.36 nmol/mmol | Standard Error 1.68 |
| Potassium Chloride | Biochemical Markers of Bone Turnover | -0.14 nmol/mmol | Standard Error 1.71 |
| Microcrystalline Cellulose | Biochemical Markers of Bone Turnover | 0.5 nmol/mmol | Standard Error 1.61 |