Prognosis of hyponatremia in elderly patients with fragility fractures

Assocıatıons between mıld hyponatremıa and gerıatrıc syndromes ın outpatıent settıngs

PURPOSE

The impact of mild hyponatremia on geriatric syndromes is not clear. Our aim was to determine associations between mild hyponatremia and results of comprehensive geriatric assessment tools in outpatient settings.

METHODS

We reviewed medical records of 1255 consecutive outpatient elderly subjects and compared results of comprehensive geriatric assessment measures among patients with mild hyponatremia (serum Na⁺ 130-135 mEq/L) versus normonatremia (serum Na⁺ 136-145 mEq/L). The comprehensive geriatric assessment measures included the Basic and Instrumental Activities of Daily Living, Mini Mental State Examination, Geriatric Depression Score, Tinetti Mobility Test, the Timed Up&Go Test, the Mini Nutritional Assessment, the handgrip test, the Insomnia Severity Index, polypharmacy, recurrent falls, urinary incontinence, orthostatic hypotension, and nocturia.

RESULTS

Of the 1255 patients, 855 were female (68.1%), and the mean age was 73.7 ± 8.3 years. Mild hyponatremia was detected in 108 patients (8.6%). The median serum sodium was 140.5 [interquartile range (IQR) 138.4-141.8] versus 133.8 [IQR, 132.3-134.2] in normonatremia and mild hyponatremia groups, respectively (p < 0.001). The only significant difference for comorbidities between normonatremia and mild hyponatremia groups was the frequency of hypertension (66.9% versus 76.7%, respectively (p = 0.041). None of the comprehensive geriatric assessment tools conferred a significant association with mild hyponatremia. Of the 1061 subjects with available survival data, 96 (9.0%) deceased within 3-4 years of follow-up (p = 0.742). Hyponatremia as an independent variable did not have a significant effect on mortality in univariate logistic regression analysis (OR 1.13, 95% CI 0.55-2.33, p = 0.742).

CONCLUSION

Mild hyponatremia does not apparently affect results of geriatric assessments significantly. Whether particular causes of hyponatremia may have different impacts should be tested in further studies.

Delayed postoperative hyponatremia after endoscopic transsphenoidal surgery for pituitary adenoma

BACKGROUND

Hyponatremia generally occurs after transsphenoidal surgery (TSS) in a delayed fashion. Most patients with delayed postoperative hyponatremia (DPH) are asymptomatic or only express non-specific symptoms; consequently, DPH is associated with prolonged hospitalization. No consensus has been reached on which patients are at greatest risk of developing DPH. We reviewed patients with DPH and evaluated predictive factors for DPH.

METHODS

We retrospectively analyzed 107 consecutive patients who underwent endoscopic TSS for pituitary adenoma (January 2010-December 2016). Patients with DPH (hyponatremia group) and without DPH (normonatremia group) were compared according to their nadir sodium levels on postoperative days 3 to 10. We documented the patients' demographics, clinical features, and postoperative physiological characteristics.

RESULTS

Twenty-five (23.4%) patients developed DPH after endoscopic TSS. The patients' mean age was 54 ± 17 years, and 63.6% of the patients were female. The overall prevalence of DPH was 23.4%. The non-parametric χ2 test and the Mann-Whitney U test revealed statistically significant differences in age, use of antihypertensive drugs, nonfunctioning pituitary adenoma, and higher yet normal preoperative thyroid-stimulating hormone level between the hyponatremia and normonatremia groups (P < 0.05). Logistic regression analysis revealed that only older age was a useful independent predictive factor for DPH (odds ratio, 1.05; 95% confidence interval, 1.01-1.08; P = 0.01). The serum sodium levels on postoperative day 2 were significantly lower in the hyponatremia than normonatremia group (P < 0.01) and were negatively correlated with age (r = - 0.25, P < 0.05). The cut-off age for predicting DPH was 55 years. The hospital stay was significantly longer in the hyponatremia than normonatremia group (P < 0.01).

CONCLUSIONS

Age of more than 55 years was an independent predictive factor for DPH even after adjusting for potential confounders. Older age was negatively correlated with the serum sodium level on postoperative day 2. Preventing early decreases in the sodium level could reduce the risk of DPH.

TRIAL REGISTRATION

1707-027.

Serum sodium level variability as a prognosticator in older adults

Our aim was to explore biological variation of serum sodium levels as a method of quantifying health risk in older adults. We investigated whether dynamic changes in serum sodium levels could provide additional prognostic information to standard predictors of mortality in older people. Analysis of routinely collected clinical datasets containing information on demographics, hospitalisation, biochemistry, haematology and physical function for Dundee in-patient rehabilitation services, between 1999 and 2011. Older people admitted to inpatient rehabilitation following an acute medical or surgical hospitalisation. Five dynamic measures of sodium levels homeostasis - minimum, maximum, standard deviation, and minimum and maximum deviation from mean - were derived for each individual, using biochemistry data from the year preceding their rehabilitation discharge. Cox regression models tested for associations with time to death. Covariates included age, sex, discharge Barthel score, co-morbid diagnoses, haemoglobin, albumin and eGFR. 3021 patients were included (mean age 84 years, 1776 (58.8%) females). 1651 (54.7%) patients experienced hyponatraemia and 446 (14.8%) became hypernatraemic. Mean sodium was correlated with all mean, minimum and SD of sodium. Kaplan-Meier survival curves showed that those without sodium perturbations had the best mortality outcomes, whilst those with both hyponatremia and hypernatremia had the worst. Multivariate Cox regression showed that standard deviation and hypernatraemia were significant predictors of death in non-adjusted models, but not fully adjusted models. All dynamic measures of dysnatraemia were associated with increased mortality risk, but failed to add predictive value to established static measures after adjusting for covariates.

Prevalence of Hyponatremia in Elderly Patients with Hip Fractures: A Two-Year Study

OBJECTIVE

This study investigated the prevalence of hyponatremia in elderly patients (≥65 years old) with hip fractures.

SUBJECTS AND METHODS

All records containing clinical and laboratory data on the 334 elderly patients admitted to the San Giovanni di Dio e Ruggi d'Aragona Hospital of Salerno, Italy, with hip fractures during 2014 and 2015, were retrieved from the hospital database. Patients were divided into 4 groups, according to their sex and the type of hip fracture. Sodium serum concentrations were retrieved from the medical records. Hyponatremia was defined as the presence of at least 1 episode of hyponatremia during the hospital stay.

RESULTS

Of 334 elderly patients, hyponatremia was found in 64 (19%). The prevalence of hyponatremia was 18% (28/157) for female patients with extracapsular proximal femoral fracture, 22% (17/79) for female patients with intracapsular proximal femoral fracture, 20% (12/60) for male patients with extracapsular proximal femoral fracture, and 18% (7/38) for male patients with intracapsular proximal femoral fracture.

CONCLUSION

There was a high prevalence of hyponatremia in the elderly patients with hip fractures. Hence, serum sodium concentrations should be regularly assessed to prevent occurrence of hyponatremia.