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Biomedical subjects

M Rodríguez García

Publications and source records attributed to M Rodríguez García.

At least 19 recordsLinked to original sources
PubMed2003

[Review of the concept of vitamin D "sufficiency and insufficiency"].

There has been a poor consensus in defining normal levels of 25(OH) D. It has been traditionally recognized that 25(OH)D serum levels below 5-7 ng/ml induce osteomalacia, serum levels below 10-12 ng/ml induce secondary hyperparathyroidism and osteoporosis, and serum levels above 18-20 ng/ml are usually considered normal or adequate. Due to the results obtained in several studies, a more functional classification has recently been proposed defining serum 25(OH)D levels > 40 ng/ml or > 100 nmol/l as "desirable", serum levels between 20 and 40 ng/ml or 50 and 100 nmol/l as hypovitaminosis D, levels between 10 and 20 ng/ml or 25 and 50 mmol/l as vitamin D insufficiency and 25(OH)D levels below 10 ng/ml or 25 nmol/l as deficient. These new cut-off levels, suggest that, in the past, we had been using a wrong statistical approach for defining "normal serum 25(OH)D levels". In agreement with this new classification, in a recent study conducted in a random sample of our population, a high prevalence of low levels of 25(OH)D and secondary hyperparathyroidism was found. In our study, only in those people having "excellent" renal function, representing only 15% of the sample (serum creatinine < 1 mg/dl in men and < 0.8 in women, mean age of 68 years) hyperparathyroidism was not diagnosed despite observing 25(OH)D serum levels around 18-30 ng/ml or 45-75 nmol/l). In the remaining people (85% of the sample), who showed the expected serum creatinine increments according to their age, secondary hyperparathyroidism was avoided only if the serum 25(OH)D levels were higher than 30 ng/ml or 75 nmol/l. These remarkable findings demonstrate the importance of maintaining higher 25(OH)D levels--in addition to normal calcitriol levels--in order to avoid stimulation of the parathyroid gland. In 87 patients with a functioning renal transplantation only a 11.5% of they had levels of 25(OH)D higher than 30 ng/ml and it was correlated with PTH. These remarkable findings demonstrate the importance of maintaining higher 25(OH)D levels--in addition to normal calcitriol levels--in order to avoid stimulation of the parathyroid gland in aged people. Thus, the deficiency or even "subtle deficiency" of 25(OH)D, currently neglected in the daily management of patients with chronic renal failure, may play an important role in the maintenance of hormonal and mineral homeostasis.

Aged↗
PubMed2003

[Osteoporosis, estrogens, and bone metabolism. Implications for chronic renal insufficiency].

The relationship between estrogens, bone metabolism and osteoporosis is well known. Chronic renal failure in women is associated with menstrual disorders, lower bone mineral density and increased risk of fractures. However, most studies on renal osteodystrophy have not taken into account the role of oestrogen deficiency, its interaction, and the possible benefits of hormone replacement therapy (HRT) in uremic women. According to these limitations and the actual evidence of benefits and risks of HRT, we conclude that: a) Osteoporosis must be evaluated as a part of renal osteodystrophy; b) HRT would be considered in women with climateric symptoms and osteoporosis, and should not be used for prevention of cardiovascular disease, and c) Clearly we need to do more studies related to osteoporosis and estrogens in CRF, but right now we have to try to optimize bone turnover in our uremic patients.

Adult↗
PubMed2003

[Estimation of bone mass of hemodialysis patients by digital radiologic radiogrammetry (DXR)].

Bone mass (BMD) may be evaluated by digital X-ray radiogrammetry (DXR) which it is estimated from multiple cortical measures carried out on five regions of interest over a simple hand-forearm X-ray film. We included 168 HD patients (108 men and 60 women; 63 +/- 14 and 66 +/- 12 years old respectively--p < 0.05-) coming from seven HD units in Asturias. We performed a hand-forearm X-ray, an epidemiologic questionnaire and we revised their medical and analytical records. As the normative data we used the measurements of a random sample of 247 subjects from our own population. The prevalence of osteoporosis was 7% and 40% in men and women respectively. BMD was correlated with weight (r = 0.346), time on HD (r = -0.188), time on treatment (r = -0.235). The porosity was correlated with PTH levels.

Absorptiometry, Photon↗
PubMed2003

[Prevalence of vertebral fractures and aortic calcifications in hemodialysis patients: comparison with a population of the same age and sex].

Dialysis patients have bone metabolic disorders and a higher prevalence of fractures, principally peripheral fractures. However, there are few studies focusing on the prevalence of vertebral fractures. Moreover, aortic calcifications are very common and are an independent predictive factor of vascular morbidity and mortality. The objective of this study was to assess the prevalence of vertebral fractures and vascular calcifications in haemodialysis (HD) patients (n = 99), in comparison with a random sample of general population of similar age and from the same geographical area (n = 624) and study their relationship with clinical, biochemical and therapeutical data. The prevalence of vertebral fractures in HD patients and general population was 19.1% and 24.1% respectively (non-significant statistical differences). In both, sexes, the presence of vertebral fractures was positively associated with age, mean maximum Ca, mean maximum CaxP. In women, time in HD was positively associated as well. On the other hand, the prevalence of aortic calcifications was much higher in HD patients (77.9% vs 37.5%, p < 0.001). HD was a risk factor for aortic calcification in women [OR = 7.7 (IC 95% = 2.6-22.9)] as in men [OR = 5 (IC 95% = 1.9-12.9)]. Severe vascular calcifications were more frequent in HD patients, it reached 57.4% compared with 17% of general population (p < 0.001). Both, in women (64.5% vs 13.3% p < 0.001) and in men (51.4% vs 20.9%), respectively (p < 0.001). In conclusion, the prevalence of vertebral fractures was similar in HD patients and in general population. Nevertheless, frequency and severity of aortic calcifications was higher in HD patients.

Aged↗
PubMed2002

[Calcitriol dose optimization in the treatment of secondary hyperparathyroidism during dialysis. Results at 6 months].

One recent report have recommended to start calcitriol therapy with a dose according to PTH levels, rather than starting with a fixed dose increasing it according to PTH response. As there are no clinical studies supporting this strategy we tested his hypothesis. Haemodialysis patients from 28 centres (N = 141) were included, the aim was to achieve a PTH between 100 and 285 pg/mL (goal) in 6 months. The main inclusion criteria were: serum PTH > 250 pg/mL, Ca < 10.5 mg/dL, P < 6.5 mg/dL and Ca x P < 60. Patients were divided according PTH into 4 groups and calcitriol was dosed accordingly. A (PTH 250-350; 0.5 microgram), B (PTH 351-550; 1-1.5 micrograms), C (PTH 551-750; 1.5-2 micrograms) and D (PTH < 750 pg/mL; 2-3 micrograms). PTH was measured monthly in groups A, B, C and fortnightly in D. Ca, P and Ca x P were measured fortnightly (groups A, B, C) and weekly in D. According to PTH results calcitriol was modified, reducing 50% if PTH was suppressed > 60%, and increasing 50% if PTH suppression was < 15% (fig. 1). Patients were stopped treatment and excluded from study when Ca, P and Ca x P product trespass the established inclusion criteria. The study was completed by 100 patients, 34 with strict compliance of the protocol (compliant), and 66 with one o more protocol violations, the most frequent was lack of strict adherence to the dosing regime (non compliant). Among the compliant, 82.4% reached the goal in contrast with 13.8% of the non compliant (p < 0.001) (table II). In addition, the compliant showed (all patients in all groups) a greater and significant decrease in PTH (from 616 +/- 288 to 202 +/- 82), by contrast, 21.5% of the non-compliant did not decrease--but increased--their PTH levels. The compliant showed also fewer side effects than the non-compliant (25% vs 55.6%, p < 0.006). These results demonstrate several advantages when starting calcitriol therapy with a dose proportional to the severity of HPTH.

Adult↗
PubMedDate not supplied

Intrafamilial spread of hepatitis C virus.

We studied the prevalence of antibodies against hepatitis C virus (anti-HCV) among 530 household contacts of 225 anti-HCV-positive subjects (index cases). Twenty-six (4.9%) relatives had anti-HCV, a proportion higher than that found among blood donors (175 of 22,435; 0.78%) (p less than 0.001). We did not find any differences regarding the type of relation with the index case (sexual or nonsexual). The prevalence of anti-HCV increased with the age of the relatives, with the contact time with the index case, and with the time of exposure to HCV. On the other hand, the anti-HCV was associated mainly with the existence of cirrhosis or hepatocellular carcinoma in the patient. We concluded that intrafamilial transmission may be an important mechanism in the spread of HCV.

Adolescent↗