Fluoride Action Network

Abstract

A cross-sectional study was performed to investigate the relationships between serum fluoride levels, glucose levels, and insulin secretion in a general population. A total of 330 healthy subjects (167 men; 163 women) aged between 40 and 69 years were examined. Lifestyle information was obtained using questionnaires. Blood samples were collected in the early morning, and biochemical parameters and glucose indices were measured. Serum ionic fluoride (SIF) levels were assessed using a highly sensitive method. Relationships between glucose indices and SIF levels were investigated using a multiple linear regression analysis. SIF levels positively correlated with fasting plasma glucose (FPG) and glycohemoglobin (HbA1c) levels in both sexes. In women, SIF levels negatively correlated with homeostasis model assessment insulin secretion (HOMA-B) levels. In men, the proportion of regular drinkers negatively correlated with HOMA-B, but not SIF levels. Although SIF levels < 1 umol/L were associated with reduced insulin secretion and increased FPG levels, the risk of diabetes was not elevated. These results suggest that increased SIF levels caused by a large fluoride intake and compromised renal function combined with poor lifestyle choices elevate the risk of diabetes. Further studies are warranted to elucidate the effects of fluoride on glucose metabolism.


*Original abstract online at https://link.springer.com/article/10.1007%2Fs12011-020-02415-1


 

References

1.  Whitford GM (1996) The metabolism and toxicity of fluoride. Monogr Oral Sci 16. Rev 2. 1–153

2.  Tsunoda N, Sakurai S, Tsunoda H (1986) Gastrointestinal absorption of fluoride in humans—a comparative study of NaF and CaF2. In: Humio T and Ming-Ho Yu (ed) Fluoride research 1985, studies in environmental science 27. Elsevier, Amsterdam, pp389–394

3.  Everett ET (2011) Fluoride’s effects on the formation of teeth and bones, and the influence of genetics. J Dent Res 90:552–560. https://doi.org/10.1177/0022034510384626

CAS  Article  PubMed  PubMed Central  Google Scholar

4.  Jones S, Burt BA, Petersen PE, Lennon MA (2005) The effective use of fluorides in public health. Bull World Health Organ 83:670–676

PubMed  PubMed Central  Google Scholar

5.  Rigalli A, Ballina JC, Roveri E, Puche RC (1990) Inhibitory effect of fluoride on the secretion of insulin. Calcif Tissue Int 46:333–338. https://doi.org/10.1007/bf02563825

CAS  Article  PubMed  Google Scholar

6.  Trivedi N, Mithal A, Gupta SK, Fluoride Collaborative Study Group (1993) Reversible impairment of glucose tolerance in patients with endemic fluorosis. Diabetologia 36:826–828. https://doi.org/10.1007/bf00400357

CAS  Article  PubMed  Google Scholar

7.  Itai K, Onoda T, Nohara M, Ohsawa M, Tannno K, Sato T (2010) Serum ionic fluoride concentrations are related to renal function and menopause status but no to age in a Japanese general population. Clin Chim Acta 411:263–266. https://doi.org/10.1016/j.cca.2009.11.014

CAS  Article  PubMed  Google Scholar

8.  Al-Wakeel JS, Mitwalli AH, Huraib S, Al-Mohaya S, Abu-Aisha H, Chaudhary AR, Al-Majed SA, Memon N (1997) Serum ionic fluoride levels in haemodialysis and continuous ambulatory peritoneal dialysis patients. Nephrol Dial Transplant 12:1420–1424. https://doi.org/10.1093/ndt/12.7.1420

CAS  Article  PubMed  Google Scholar

9.  Cowell DC, Taylor WH (1981) Ionic fluoride: a study of its physiological variation in man. Ann Clin Biochem 18:76–83. https://doi.org/10.1177/000456328101800204

CAS  Article  PubMed  Google Scholar

10.  Torra M, Rodamilans M, Corbella J (1998) Serum and urine fluoride concentration: relationships to age, sex, and renal function in a non-fluoridated population. Sci Total Environ 220:81–85. https://doi.org/10.1016/s0048-9697(98)00248-4

CAS  Article  PubMed  Google Scholar

11.  Matsuo S, Imai E, Horio M, Yasuda Y, Tomita K, Nitta K (2009) Revised equations for estimated GFR from serum creatinine in Japan. Am J Kidney Dis 53:982–992. https://doi.org/10.1053/j.ajkd.2008.12.034

CAS  Article  PubMed  PubMed Central  Google Scholar

12.  Haffner SM, Miettinen H, Stern MP (1997) The homeostasis model in the San Antonio heart study. Diabetes Care 20:1087–1092. https://doi.org/10.2337/diacare.20.7.1087

CAS  Article  PubMed  Google Scholar

13.  Itai K, Tsunoda H (2001) Highly sensitive and rapid method for determination of fluoride ion concentrations in serum and urine using flow injection analysis with a fluoride ion-selective electrode. Clin Chim Acta 308:163–171. https://doi.org/10.1016/s0009-8981(01)00488-0

CAS  Article  PubMed  Google Scholar

14.  Kennedy JW, Carey RN, Coolen RB, Garber CC, Lee HT, Levine JB, Osberg IM (1999) Evaluation of precision performance of clinical chemistry devices: approved guideline. NCCLS, EP5-A, Vol19, No.2, Wayne, Pennsylvania

15.  Menoyo I, Riglli A, Puche RC (2005) Effect of fluoride on the secretion of insulin in the rat. Antidiabetica 8:455–460. https://doi.org/10.1055/s-0031-1296888

Article  Google Scholar

16.  Rigalli A, Alloatti R, Menoyo I, Puche RC (1995) Comparative study of the effect of sodium fluoride and sodium monofluorophosphate on glucose homeostasis in the rat. Arzneimittelforschung 45:289–292

CAS  PubMed  Google Scholar

17.  Fluegge K (2016) Community water fluoridation predicts increase in age-adjusted incidence and prevalence of diabetes in 22 states from 2005 and 2010. J Water Health 14:864–877. https://doi.org/10.2166/wh.2016.012

Article  PubMed  PubMed Central  Google Scholar

18.  Walton C, Godsland IF, Proudler AJ, Wynn V, Stevenson JC (1993) The effects of the menopause on insulin sensitivity, secretion and elimination in non-obese, healthy women. Eur J Clin Invest 23:466–473. https://doi.org/10.1111/j.1365-2362.1993.tb00792.x

CAS  Article  PubMed  Google Scholar

19.  Otsuki M, Kasayama S, Morita S, Asanum N, Saito H, Mukai M, Koga M (2007) Menopause, but not age, is an independent risk factor for fasting plasma glucose levels in nondiabetic women. Menopause 14:404–407. https://doi.org/10.1097/01.gme.0000247014.56254.12

Article  PubMed  Google Scholar

20. Waki K, Noda M, Sasaki S, Matsumura Y, Takahashi Y, Isogawa A, Ohashi Y, Kadowaki T, Tsugane S, JPHC Study Group (2005) Alcohol consumption and other risk factors for self-reported diabetes among middle-aged Japanese: a population-based prospective study in the JPHC study cohort I. Diabet Med 23:323–331. https://doi.org/10.1111/j.1464-5491.2004.01403.x

Article  Google Scholar

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Author information

Affiliations

Contributions

Itai K made a substantial contribution to the design of the study, performed the analysis, and drafted the manuscript. Okayama A designed the study and interpreted the results obtained. Onoda T, Nohara M, and Kuribayashi T made a substantial contribution to the design of the study and contributed to the analysis and interpretation of the results obtained. Ohsawa M, Tanno K, and Mori M contributed to the analysis and interpretation of the results obtained. All of the authors have revised the manuscript for important intellectual content and approved the final written manuscript.

Corresponding author

Correspondence to Kazuyoshi Itai.


*Original abstract online at https://link.springer.com/article/10.1007%2Fs12011-020-02415-1