Çıkı Kısmet, Kahraman Ayça Burcu, Akar Halil Tuna, Yıldız Yılmaz, Dursun Ali, Tokatlı Ayşegül, Coşkun Turgay, Sivri Serap
Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
Postgrad Med. 2025 Jan;137(1):86-92. doi: 10.1080/00325481.2024.2444873. Epub 2024 Dec 24.
It has been reported that phenylalanine (Phe)-restricted diets may have negative effects on bone health in patients with classical phenylketonuria (cPKU). We aimed to evaluate bone mineral density (BMD) in adults with cPKU and determine the risk factors associated with low BMD.
Eighty adult patients with cPKU were examined, including 41 women and 39 men. The age range was 18.3-39.4 years (median 22.8). The femoral and lumbar BMD were measured by dual energy X-ray absorptiometry. The patients were evaluated in two groups with low (Z-score ≤-2) and normal BMD (Z-score > -2).
Low BMD was detected in 20 patients (25%). The low BMD group had significantly more males (75% vs 40%, < 0.01) and lower mean body mass index (BMI, 22.4 vs 24.5 kg/m, = 0.02). Paradoxically, mean blood calcium and 25-hydroxy vitamin D levels were higher in the low BMD group, but only marginally (10.0 vs 9.8 mg/dl and 25.1 vs 21.0 µg/L respectively, < 0.05). The groups did not differ significantly with regards to age, mean Phe levels at diagnosis, median Phe levels above the age of 12 years, other nutritional parameters or vitamin-mineral supplementation. There was no history of clinical fractures.
Although osteopenia, osteoporosis and low BMD have been reported in PKU, conflicting data also exist. Our study of a large adult cPKU cohort strongly supports previously published limited data that suggest male sex and low BMI confer a higher risk for low BMD in cPKU; and age, Phe levels and dietary adherence do not. In our study, although the patients were young, low BMD was quite common (25%). Bone health should be evaluated even in young adults with cPKU, especially in males and those with low BMI, regardless of treatment compliance and vitamin-mineral status. Prospective studies reporting on clinical outcomes such as bone pain or fractures will be valuable in the coming years.
据报道，苯丙氨酸（Phe）限制饮食可能会对经典型苯丙酮尿症（cPKU）患者的骨骼健康产生负面影响。我们旨在评估成年cPKU患者的骨密度（BMD），并确定与低骨密度相关的风险因素。
对80例成年cPKU患者进行了检查，其中包括41名女性和39名男性。年龄范围为18.3 - 39.4岁（中位数为22.8岁）。采用双能X线吸收法测量股骨和腰椎的骨密度。将患者分为骨密度低（Z评分≤ -2）和骨密度正常（Z评分> -2）两组进行评估。
20例患者（25%）检测出骨密度低。骨密度低的组中男性明显更多（75%对40%，P < 0.01），平均体重指数更低（BMI，22.4对24.5 kg/m²，P = 0.02）。矛盾的是，骨密度低的组平均血钙和25 - 羟基维生素D水平更高，但只是略高（分别为10.0对9.8 mg/dl和25.1对21.0 μg/L，P < 0.05）。两组在年龄、诊断时的平均苯丙氨酸水平、12岁以上的苯丙氨酸中位数水平、其他营养参数或维生素 - 矿物质补充方面无显著差异。无临床骨折病史。
虽然苯丙酮尿症患者中已报道有骨质减少、骨质疏松和低骨密度情况，但也存在相互矛盾的数据。我们对大量成年cPKU队列的研究有力地支持了先前发表的有限数据，即男性和低BMI会使cPKU患者发生低骨密度的风险更高；而年龄、苯丙氨酸水平和饮食依从性则不会。在我们的研究中，尽管患者年轻，但低骨密度相当常见（25%）。即使是年轻的成年cPKU患者，也应评估骨骼健康，尤其是男性和BMI低的患者，无论其治疗依从性和维生素 - 矿物质状况如何。未来几年，报告骨痛或骨折等临床结果的前瞻性研究将很有价值。
