Case Control Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Oct 15, 2020; 11(10): 416-424
Published online Oct 15, 2020. doi: 10.4239/wjd.v11.i10.416
Importance of serum phosphate in elderly patients with diabetes mellitus
Vaia D Raikou, Despina Kyriaki, Sotiris Gavriil
Vaia D Raikou, Department of Nephrology, Doctors’ Hospital, Athens 11257, Greece
Despina Kyriaki, Department of Nuclear Medicine, General Hospital “LAΪKO”, Athens 11527, Greece
Sotiris Gavriil, Department of Bariatric Surgery, Doctors’ Hospital, Athens 11257, Greece
Author contributions: Raikou VD and Gavriil S designed the research plan, data collection, biostatistic analyses and manuscript writing; Kyriaki D performed the biochemical measurements and immunoassays; all authors have read and approved the final manuscript.
Institutional review board statement: The study was approved by the ethics committee of Doctors’ Hospital (Athens, Greece).
Informed consent statement: All patients gave informed consent.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at vraikou@med.uoa.gr.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Corresponding author: Vaia D Raikou, PhD, Chief Doctor, Department of Nephrology, Doctors’ Hospital, 26 Kefallinias, Athens 11257, Greece. vraikou@med.uoa.gr
Received: February 4, 2020
Peer-review started: February 4, 2020
First decision: April 22, 2020
Revised: May 11, 2020
Accepted: August 25, 2020
Article in press: August 25, 2020
Published online: October 15, 2020
Processing time: 252 Days and 19.2 Hours
Abstract
BACKGROUND

Metabolic disturbances including changes in serum calcium, magnesium or phosphate (P) influence the prevalence of type 2 diabetes mellitus (DM). We assessed the importance of serum P in elderly patients with type 2 DM vs non-diabetes mellitus (non-DM) in relation to renal function.

AIM

To determine the association between serum P and serum glucose or insulin resistance in diabetic and non-diabetic patients.

METHODS

One hundred-ten subjects with a mean age of 69.02 ± 14.3 years were enrolled. Twenty-nine of the participants had type 2 DM (26.4%). The incidence of hypertension, smoking and receiving vitamin D (vitD) derivates were recorded. The participants were classified by both estimated glomerular filtration rate (eGFR) and albuminuria categories according to the Kidney Disease Improving Global Outcomes 2012 criteria.

RESULTS

We divided the patients in two groups according to the P cut-off point related to DM value. A comparison between high and low P showed that body mass index 30.2 ± 6.3 vs 28.1 ± 4.6 (P = 0.04), mean glucose 63.6 vs 50.2 (P = 0.03), uric acid 6.7 ± 1.6 vs 6.09 ± 1.7 (P = 0.05), mean intact-parathyroid hormone 68.06 vs 47.4 (P = 0.001), systolic blood pressure 147.4 ± 16.7 vs 140.2 ± 16.1 (P = 0.02), mean albuminuria 63.2 vs 50.6 (P = 0.04) and eGFR 45.6 ± 22.1 vs 55.4 ± 21.5 (P = 0.02) were significantly different. χ2 tests showed a significant association between high P and DM, hypertension, receiving vitD, smoking and eGFR stage (χ2 = 6.3, P = 0.01, χ2 = 3.9, P = 0.03, χ2 = 6.9, P = 0.009, χ2 = 7.04, P = 0.01 and χ2 = 7.36, P = 0.04, respectively). The adjusted model showed that older age, female gender and increased body mass index were significant predictors of type 2 DM when entering the covariates.

CONCLUSION

High serum P contributes to vascular and metabolic disturbances in elderly patients with type 2 DM and renal impairment.

Keywords: Serum phosphate; Diabetes mellitus; Renal disease; Old age; Albuminuria; Vitamin D

Core Tip: Despite high serum phosphate (P) being associated with hypertension, albuminuria, smoking, low estimated glomerular filtration rate and metabolic disorders, traditional factors including older age, female gender and high body mass index were proved to be potential predictors of type 2 diabetes mellitus. Serum P levels were similar in diabetic and non-diabetic patients and the association between serum P and serum glucose or insulin resistance was found to be non-significant in both diabetic and non-diabetic patients, which was discordant with previous reports, due to renal dysfunction.