Relationship between renal function and diabetic osteoporosis in the diabetics

Yurong XI; Decai CHEN; Yuan ZHANG

ABSTRACT

BACKGROUND:

Most of the literatures only reported that there is a great difference between diabetics who have a high 24-hour urinary albumin excretion rate and those without renal damage, but there is no obvious difference between cases of microalbuminuria and those without renal damage.

OBJECTIVE:

To probe into the relationship between diabetic nephropathy and osteoporosis.

DESIGN:

A case-control study.

SETTING:

Department of Endocrinology, West China Hospital of Sichuan University.

PARTICIPANTS:

According to the diagnostic standard set by the American Diabetes Association in 1997 (fasting blood glucose ≥ 7 mmol/L,postprandial blood glucose ≥ 11.1 mmol/L), 96 diabetic patients were selected, including 56 males ＜ 60 years old and 40 females who had not entered the menopausal period, excluding the influence of age and osteoporosis caused by menopause. The average age of the subjects was (48.7±10.5)years, their duration were from one month to twenty-one years with the aver age of (7.85±2.56) years, and their general information had no significant differences.

METHODS:

According to the urine albumine excretion rate and renal function, the patients were divided into four groups normal albuminuria group (n=48), microalbuminuria group (n=28), macroalbuminuria group (n=15), renal failure group (n=5). The bone mineral densities of lumbar spines (L2-4), femoral neck, Ward's triangle and trochanter were detected with Dual energy X-ray absorptiometry, and then the fasting blood glucose,2-hour postprandial blood glucose, glycosylated hemoglobin A, alkaline phosphatase, calcium, phosphorus, blood urea nitrogen, creatinine and urine albumine excretion rate were compared between the patients with and without osteoporosis.MAIN OUTCOME

MEASURES:

The fasting blood glucose, 2-hour postprandial blood glucose, glycosylated hemoglobin A, alkaline phosphatase, calcium, phosphorus, blood urea nitrogen, creatinine and urine albumine excretion rate, as well as the bone mineral density, were observed in all the patients.

RESULTS:

The L2-3 bone mineral density in the macroalbuminuria group was significantly different from that in the microalbuminuria group (P ＜ 0.05). The proximal femur bone mineral density in the microalbuminuria group was significantly different from that in the normal albuminuria group (P ＜ 0.05). The bone mineral densities of proximal femur and lumbar spine in the renal failure group were significantly decreased as compared with those in the other groups (P ＜ 0.01). The disease course,glycosylated hemoglobin A, alkaline phosphatase and body mass index were significantly different between the patients with and without osteoporosis (P ＜ 0.05).

CONCLUSION:

The incidence rate of osteoporosis is increased with the aggravation of nephropathy, and diabetic nephropathy may be closely correlated with the decrease of bone mineral density and the occurrence of osteoporosis.