Lower bone strength in young patients with Fontan circulation compared to controls.

OBJECTIVES: Previous reports indicate bone deficits in patients with Fontan circulation. However, the consequences of these deficits on bone strength and when these changes occur are unclear. AIM: To compare the tibial bone strength-strain index between young patients (6-19 years) with Fontan circulation and age- and sex-matched controls, and to determine strength-strain-index in subgroups of children (6-12 years) and adolescents (13-19 years) versus controls. METHOD: The tibia was examined with peripheral quantitative CT. Based on the assessed data, bone strength-strain index was calculated in the lateral and anterior-posterior directions. RESULTS: Twenty patients with Fontan and twenty controls (mean age 13.0 ± 4.4 years; 50% females) were examined. Patients had a lower strength-strain index in the lateral direction compared to controls (808.4 ± 416.8mm3 versus 1162.5 ± 552.1mm3, p = 0.043). Subgroup analyses showed no differences regarding strength-strain index in children (6-12 years) with Fontan circulation compared to controls. However, the adolescents (13-19 years) with Fontan circulation had lower strength-strain indexes in both the lateral and anterior-posterior directions compared to controls (1041.4 ± 299.8mm3 versus 1596.4 ± 239.6mm3, p < 0.001, and 771.7 ± 192.4mm3 versus 1084.9 ± 215.0mm3, p = 0.004). When adjusted for height, there were differences between patients (6-19 years) and controls in strength-strain indexes in both the lateral and anterior-posterior directions. In subgroup analyses, the results remained robust. CONCLUSION: Young patients (6-19 years) with Fontan circulation have a lower strength-strain index in the tibia compared to controls. Subgroup analyses show that this deficit is mainly driven by the differences in adolescents (13-19 years), which might suggest that bone strength decreases with age.

Low bone mineral density in adults with complex congenital heart disease.

AIMS: The majority of children with complex congenital heart disease (CHD) survive into adulthood due to advances in medical care. Adult patients with CHD have an increased incidence of diagnoses related to ageing such as heart failure, dementia, cancer and sarcopenia, despite a relatively low age. They also have a shorter life expectancy. It is unknown if their bone structures also show signs of premature ageing. We therefore investigated Bone Mineral Content (BMC) and bone mineral density (BMD) in an adult population with complex CHD. METHODS: The total body BMC and BMD was examined using dual energy X-ray absorptiometry (DXA) in 73 adults with complex CHD (mean age 35.8 ± 14.3, women n = 22) and 73 age and sex matched controls. RESULTS: The adults with complex CHD had lower total body BMC (2.6 ± 0.5 kg vs. 2.9 ± 0.5 kg, p < 0.001) and BMD (1.18 ± 0.12 g/cm2vs. 1.26 ± 0.11 g/cm2, p < 0.001) compared to controls. BMD was lower for patients with single ventricle physiology and for the other complex diagnoses, and it persisted after correction for most common risk factors for osteoporosis. CONCLUSION: Adults with complex CHD have reduced total body BMC and BMD compared to healthy controls. These results are a sign of frailty that conforms with other previously reported signs of premature ageing. The risk of osteoporosis is low in our relatively young population, but it is assumed to increase with ageing. We recommend that clinicians pay close attention to risk factors for osteoporosis, and are generous in administering DXA-measurements in order to prevent future fractures among adults with complex CHD.

Sarcopenia is common in adults with complex congenital heart disease.

BACKGROUND: Adults with complex congenital heart disease (CHD) have reduced aerobic capacity and impaired muscle function. We therefore hypothesized that patients have a lower skeletal muscle mass and higher fat mass than controls. METHODS: Body composition was examined with full body Dual-Energy x-ray Absorptiometry (DXA) in 73 patients with complex CHD (mean age 35.8 ±â€¯14.3, women n = 22) and 73 age and sex matched controls. Patients fulfilling criteria for low skeletal muscle mass in relation to their height and fat mass were defined as sarcopenic. RESULTS: Male patients (n = 51) were shorter (177.4 ±â€¯6.6 cm vs. 180.9 ±â€¯6.7 cm, p = 0.009) and weighed less (76.0 ±â€¯10.8 kg vs. 82.0 ±â€¯12.4 kg, p = 0.01) than controls. Also, patients had a lower appendicular lean mass-index (ALM-index) (7.57 ±â€¯0.97 kg/m2vs. 8.46 ±â€¯0.90 kg/m2, p < 0.001). Patients' relative tissue fat mass (27.9 ±â€¯7.0% vs. 25.4 ±â€¯8.6%, p = 0.1) did not differ. Forty-seven percent of the men (n = 24) were classified as sarcopenic. Female patients (n = 22) were also shorter (163.5 ±â€¯8.7 cm vs. 166.7 ±â€¯5.9 cm, p = 0.05) but had a higher BMI (25.7 ±â€¯4.2 vs. 23.0 ±â€¯2.5, p = 0.02) than controls. Patients also had a lower ALM-index (6.30 ±â€¯0.75 vs. 6.67 ±â€¯0.55, p = 0.05), but their relative body fat mass (40.8 ±â€¯7.6% vs. 32.0 ±â€¯7.0%, p < 0.001) were higher. Fifty-nine percent of the women (n = 13) were classified as sarcopenic. CONCLUSIONS: The body composition was altered toward lower skeletal muscle mass in patients with complex CHD. Approximately half of the patients were classified as sarcopenic. Contrary to men, the women had increased body fat and a higher BMI. Further research is required to assess the cause, possible adverse long-term effects and whether sarcopenia is preventable or treatable.