World Osteoporosis Day | What does poor kidney function have to do with osteoporosis?

October 20th is World Osteoporosis Day.

With the aging of the population, osteoporosis has become a health problem around the world. In my country, the incidence of osteoporosis among people over 60 years old is 40% to 50%, and there are more than 100 million osteoporosis patients nationwide! The male to female ratio is 3:7, and 80% of them are elderly patients.

Osteoporosis is a common bone disease, which is mainly manifested by decreased bone density, thinning bones and brittle bones. Osteoporosis is divided into two categories: primary and secondary. Primary osteoporosis is mainly related to age and the decline of estrogen levels in postmenopausal women; secondary osteoporosis refers to osteoporosis caused by certain diseases or drugs.

For example, in the case of Master Wen below, his osteoporosis was secondary osteoporosis caused by kidney disease.

Master Wen, 50 years old, started regular hemodialysis treatment for "chronic nephritis" 11 years ago. During this period, the control of blood phosphorus and parathyroid hormone (PTH) has not been ideal, and the parathyroid hormone is even dozens of times higher than that of normal people. During a dialysis process three years ago, Master Wen directly fractured his femur due to a normal little action - a small sneeze. Later, after Master Wen underwent femoral internal fixation and a series of rehabilitation exercises, he finally stood up gradually. Then, Master Wen underwent parathyroidectomy. At present, Master Wen's blood phosphorus and parathyroid hormone have both reached the standard, and he can walk like a normal person.

Kidneys are important metabolic organs in the human body that can maintain water, electrolyte and acid-base balance. When renal function is impaired, calcium and phosphorus metabolism will be affected. Because of renal insufficiency, phosphorus excretion in urine is reduced, phosphorus accumulates in the body, inducing hyperphosphatemia. Increased blood phosphorus will lead to reduced calcium absorption, causing hypocalcemia. At this time, in order to correct this imbalance, our body will stimulate the parathyroid glands to secrete parathyroid hormone. The main function of this hormone is to increase blood calcium, reduce blood phosphorus, and maintain the balance of calcium and phosphorus metabolism in the body. The way parathyroid hormone regulates calcium and phosphorus metabolism is mainly to promote the release of calcium in bones and the excretion of phosphorus in urine, so that calcium in bones runs into the blood, thereby increasing our blood calcium concentration. The consequence of this compensation will lead to the loss of calcium ions in bones, bones become more and more brittle, and finally cause osteoporosis. Osteoporosis can cause bone pain, fractures, increased disability and mortality in patients.

Therefore, we must detect it early and actively prevent and treat it to reduce the occurrence of osteoporosis.

Osteoporosis rehabilitation treatment

There are four principles of rehabilitation treatment:

1. Osteoporosis should be diagnosed and treated early; go to the hospital in time and receive treatment under the guidance of doctors and other professionals.

2. Eat more foods rich in calcium and protein. The recommended daily protein intake is 0.8-1.0g/kg, and consume 300ml of milk every day; limit the intake of alcohol, coffee and carbonated drinks, quit smoking, etc.

3. Get plenty of sunlight exposure, with the exposure time being >30 minutes a day, preferably from 11 a.m. to 3 p.m.;

4. Exercise therapy and physical therapy; osteoporosis requires preparation for long-term treatment.

Exercise rehabilitation has many benefits

Exercise is essential for people with osteoporosis.

Proper exercise can not only promote calcium deposition and bone regeneration, increase bone density and bone strength, but also enhance muscle strength and balance ability, reducing the possibility of falls and fractures.

However, the bones of osteoporosis patients are more fragile and more prone to fractures; overly intense or incorrect exercise may lead to muscle strain or joint injury.

So, what kind of sports are suitable for elderly people with osteoporosis?

01 Aerobic exercise

Common aerobic exercises include brisk walking, swimming, cycling, aerobics, square dancing, jogging, etc., each time ≥ 30 minutes, 3-5 times/week. You can do it with your friends, which can not only make you happily stick to various activities together, but also improve your adaptability to the surrounding environment.

02 Resistance Training

You can choose an appropriate amount of load, such as elastic bands, dumbbells and other equipment, with leg and back muscle strength training as the main goal, 8-10 times for each movement, 5-10 sets, 3 times/week. It should be noted that resistance exercise is relatively strong, so it is best to do it under the guidance of professionals, and avoid exercising on your own.

03 Resilience training

Flexibility training helps increase the range of motion of the joints and improves the body's flexibility. Flexibility training suitable for elderly patients with osteoporosis includes yoga, stretching exercises, and Tai Chi.

Author: Zhong Chenyu, Department of Nephrology, The First Affiliated Hospital of Ningbo University

Reviewer: Bian Xueyan, Director of Nephrology Department, First Affiliated Hospital of Ningbo University, Standing Committee Member of the Kidney Disease Rehabilitation Committee of the Chinese Rehabilitation Medicine Association

Editor: Liang Juping; Illustration: Li Chuan (Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine)