Prednisolone is associated with a worse bone mineral density in primary adrenal insufficiency

CONTEXT

Patients with primary adrenal insufficiency (PAI) or congenital adrenal hyperplasia (CAH) receive life-long glucocorticoid (GC) therapy. Daily GC doses are often above the physiological cortisol production rate and can cause long-term morbidities such as osteoporosis. No prospective trial has investigated the long-term effect of different GC therapies on bone mineral density (BMD) in those patients.

OBJECTIVES

To determine if patients on hydrocortisone (HC) or prednisolone show changes in BMD after follow-up of 5.5 years. To investigate if BMD is altered after switching from immediate- to modified-release HC.

DESIGN AND PATIENTS

Prospective, observational, longitudinal study with evaluation of BMD by DXA at visit1, after 2.2 ± 0.4 (visit2) and after 5.5 ± 0.8 years (visit3) included 36 PAI and 8 CAH patients. Thirteen patients received prednisolone (age 52.5 ± 14.8 years; 8 women) and 31 patients received immediate-release HC (age 48.9 ± 15.8 years; 22 women). Twelve patients on immediate-release switched to modified-release HC at visit2.

RESULTS

Prednisolone showed significantly lower Z-scores compared to HC at femoral neck (-0.85 ± 0.80 vs -0.25 ± 1.16, P < 0.05), trochanter (-0.96 ± 0.62 vs 0.51 ± 1.07, P < 0.05) and total hip (-0.78 ± 0.55 vs 0.36 ± 1.04, P < 0.05), but not at lumbar spine, throughout the study. Prednisolone dose decreased by 8% over study time, but no significant effect was seen on BMD. BMD did not change significantly after switching from immediate- to modified-release HC.

CONCLUSIONS

The use of prednisolone as hormone replacement therapy results in significantly lower BMD compared to HC. Patients on low-dose HC replacement therapy showed unchanged Z-scores within the normal reference range during the study period.

BclI polymorphism of the glucocorticoid receptor and adrenal crisis in primary adrenal insufficiency

CONTEXT

Patients with primary adrenal insufficiency (PAI) or congenital adrenal hyperplasia (CAH) are at a high risk of adrenal crisis (AC). Glucocorticoid sensitivity is at least partially genetically determined by polymorphisms of the glucocorticoid receptor (GR).

OBJECTIVES

To determine if a number of intercurrent illnesses and AC are associated with the GR gene polymorphism BclI in patients with PAI and CAH.

DESIGN AND PATIENTS

This prospective, longitudinal study over 37.7 ± 10.1 months included 47 PAI and 25 CAH patients. During the study period, intercurrent illness episodes and AC were documented.

RESULTS

The study period covered 223 patient years in which 21 AC occurred (9.4 AC/100 pat years). There were no significant differences between BclI polymorphisms (CC (n = 29), CG (n = 34) and GG (n = 9)) regarding BMI, hydrocortisone equivalent daily dose and blood pressure. We did not find a difference in the number of intercurrent illnesses/patient year among BclI polymorphisms (CC (1.5 ± 1.4/pat year), CG (1.2 ± 1.2/pat year) and GG (1.6 ± 2.2/pat year)). The occurrence of AC was not significantly different among the homozygous (GG) genotype (32.5 AC/100 pat years), the CC genotype (6.7 AC/100 pat years) and the CG genotype (4.9 AC/100 pat years). Concomitant hypothyroidism was the highest in the GG genotype group (5/9), compared to others (CC (11/29) and CG (11/34)).

CONCLUSIONS

Although sample sizes were relatively small and results should be interpreted with caution, this study suggests that the GR gene polymorphism BclI may not be associated with the frequencies of intercurrent illnesses and AC.

Reduction in daily hydrocortisone dose improves bone health in primary adrenal insufficiency

OBJECTIVE

Individuals with primary adrenal insufficiency (PAI) or congenital adrenal hyperplasia (CAH) receive life-long glucocorticoid (GC) replacement therapy. Current daily GC doses are still higher than the reported adrenal cortisol production rate. This GC excess could result in long-term morbidities such as osteoporosis. No prospective trials have investigated the long-term effect of GC dose changes in PAI and CAH patients.

METHODS

This is a prospective and longitudinal study including 57 subjects with PAI (42 women) and 33 with CAH (21 women). Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry at baseline and after 2 years. Subjects were divided into three groups (similar baseline characteristics) depending on changes in daily hydrocortisone equivalent dose (group 1: unchanged 25.2±8.2  mg (mean±S.D., n=50); group 2: increased 18.7±10.3 to 25.9±12.0  mg (n=13); group 3: decreased 30.8±8.5 to 21.4±7.2  mg (n=27)).

RESULTS

Subjects in group 1 showed normal lumbar and femoral Z-scores which were unchanged over time. Group 2 subjects showed a significant decrease in femoral neck Z-scores over time (-0.15±1.1 to -0.37±1.0 (P<0.05)), whereas group 3 subjects showed a significant increase in lumbar spine and hip Z-scores (L1-L4: -0.93±1.2 to -0.65±1.5 (P<0.05); total hip: -0.40±1.0 to -0.28±1.0 (P<0.05)). No changes in BMI over time were seen within any group. Reduction in GC dose did not increase the risk of adrenal crisis.

CONCLUSION

This study demonstrates for the first time that cautious reduction in hydrocortisone equivalent doses leads to increases in BMD, whereas dose increments reduced BMD. These data emphasize the need for the lowest possible GC replacement dose in AI patients to maintain health and avoid long-term adverse effects.