Latitude

If it's on your mind and it has to do with multiple sclerosis in any way, post it here.
Post Reply
User avatar
Petr75
Family Elder
Posts: 1615
Joined: Sat Oct 19, 2013 10:17 am
Location: Czech Republic
Contact:

Latitude

Post by Petr75 »

2019 Jun 19
Melbourne School of Population & Global Health, The University of Melbourne, Melbourne, Victoria, Australia
Latitude continues to be significantly associated with the prevalence of multiple sclerosis: an updated meta-analysis.
https://www.ncbi.nlm.nih.gov/pubmed/31217172

Abstract
OBJECTIVES:
Previous studies have demonstrated a strong latitudinal gradient in multiple sclerosis (MS) prevalence. Herein, we present a meta-analysis of the latitudinal gradient of MS prevalence including studies published since our 2011 review, seeking to assess the latitudinal gradient and whether it has changed since our previous analysis.
METHODS:
Studies published up to December 2018 were located via Embase, Web of Knowledge and PubMed, using standardised search terms; data were extracted from peer-reviewed studies and these studies added to those from our previous analysis. Where age-specific data were available, prevalence estimates were age-/sex-standardised to the 2009 European population. Prevalence estimates were adjusted for study prevalence year and ascertainment methods. The latitudinal association with MS prevalence was assessed by meta-regression.
RESULTS:
A total of 94 studies met inclusion criteria, yielding 230 new prevalence points and 880 altogether with those from the prior study. There was a significant positive gradient in time-corrected MS prevalence with increasing latitude (5.27/100 000 per degree latitude), attenuating slightly to 4.34/100 000 on age-standardisation, these associations persisting on adjustment for ascertainment method. Of note, the age-standardised gradient was consistently significantly enhanced from our previous study, regardless of whether it was as-measured, time-corrected or adjusted for ascertainment methods. Certain areas, such as the Scandinavian and Atlantic Coast/Central Europe regions, showed changes in MS prevalence gradient over time, but other regional gradients were similar.
CONCLUSIONS:
This new meta-analysis confirms that MS prevalence is still strongly positively associated with increasing latitude and that the gradient is increasing, suggesting that potentially modifiable environmental factors, such as sun exposure, are still strongly associated with MS risk.
https://www.eboro.cz
ElliotB
Family Elder
Posts: 2062
Joined: Mon Feb 03, 2014 4:08 pm

Re: Latitude

Post by ElliotB »

As is always the case in studies like this, there were likely no Eskimos or Inuits included. I wonder why people who live at the most northern latitudes and have ZERO incidence of MS are never included in these type of studies! Oh well...
User avatar
NHE
Volunteer Moderator
Posts: 6227
Joined: Sat Nov 20, 2004 3:00 pm
Contact:

Re: Latitude

Post by NHE »

ElliotB wrote: Sun Aug 18, 2019 7:20 am As is always the case in studies like this, there were likely no Eskimos or Inuits included. I wonder why people who live at the most northern latitudes and have ZERO incidence of MS are never included in these type of studies! Oh well...
High omega-3 :?:
ElliotB
Family Elder
Posts: 2062
Joined: Mon Feb 03, 2014 4:08 pm

Re: Latitude

Post by ElliotB »

NHE, good point and yet researchers doing latitude studies always seem to ignore this info and all the readily available relevant facts that may easily contradict the purpose of their study.
User avatar
Petr75
Family Elder
Posts: 1615
Joined: Sat Oct 19, 2013 10:17 am
Location: Czech Republic
Contact:

Re: Latitude

Post by Petr75 »

Neuroepidemiology 2014
Application of Three Focused Cluster Detection Methods to Study Geographic Variation ..
https://www.karger.com/Article/FullText/365761

..The potential clusters of MS appear to be located in the City of Winnipeg, specifically the western and central regions of Winnipeg. As well, the southern part of the province of Manitoba had higher incidence rates than most of northern Manitoba. The BYM method may be the best approach for identifying potential clusters because it allows the investigator to control for potential confounders. Further studies are needed to explore the reason and cause of these increases, especially in broader geographic regions with evenly distributed population density.

.......................................................
Winnipeg https://en.wikipedia.org/wiki/Winnipeg
.......................................................


Vitamin D probably won't
........................................................

November 2018
Prevalence and incidence of multiple sclerosis
..Those parts of Asia, Africa and America that lie on the equator have extremely low levels of MS..
.............................
omega-3 probably won't

..........................................................

More ideas?

.........................................................
https://www.eboro.cz
ElliotB
Family Elder
Posts: 2062
Joined: Mon Feb 03, 2014 4:08 pm

Florida Key West MS Cluster

Post by ElliotB »

From 2014, the rate of multiple sclerosis in Key West is ''as high as anywhere in North America,'' according to a leading Government expert in the disease. A study by a University of Miami scientist found 23 cases of multiple sclerosis among the 30,000 longtime residents of this island resort. The Government expert, Dr. David Poskanzer, a research scientist with the National Institute of Health, said that rate had unheard of for a subtropical latitude.


This cluster was very unusual given how far South Key West is compared to where clusters are usually found. I have yet to find a theory about MS causes that you can't find exceptions to. Oh well... Someday the MS mystery will be solved, but unfortunately not today!

BUT there is ample evidence as to the benefits of diets high in Omega 3 fatty acids and low in Omega 6 and other fats.
User avatar
Petr75
Family Elder
Posts: 1615
Joined: Sat Oct 19, 2013 10:17 am
Location: Czech Republic
Contact:

Re: Latitude

Post by Petr75 »

Yes, MS is an enigma.
https://www.eboro.cz
User avatar
Petr75
Family Elder
Posts: 1615
Joined: Sat Oct 19, 2013 10:17 am
Location: Czech Republic
Contact:

Re: Latitude

Post by Petr75 »

2019 Jul 26
Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
Change in multiple sclerosis prevalence over time in Australia 2010-2017 utilising disease-modifying therapy prescription data.
https://www.ncbi.nlm.nih.gov/pubmed/31347952

Abstract
OBJECTIVE:
Determine the prevalence of multiple sclerosis (MS) in Australia in 2017 using MS-specific disease-modifying therapy (DMT) prescription data and estimate the change in prevalence from 2010.
METHODS:
DMT prescriptions were extracted from Australia's Pharmaceutical Benefits Scheme (PBS) data for January-December 2017. Percentages of people with MS using DMTs (DMT penetrance) were calculated using data from the Australian MS Longitudinal Study. Prevalence was estimated by dividing the total number of monthly prescriptions by 12 (except alemtuzumab), adjusted for DMT penetrance and Australian population estimates. Prevalences in Australian states/territories were age-standardised to the Australian population. Comparisons with 2010 prevalence data were performed using Poisson regression.
RESULTS:
Overall DMT penetrance was 64%, and the number of people with MS in Australia in 2017 was 25,607 (95% confidence interval (CI): 24,874-26,478), a significant increase of 4324 people since 2010 (p < 0.001). The prevalence increased significantly from 95.6/100,000 (2010) to 103.7/100,000 (2017), with estimates highest in Tasmania in 2017 (138.7/100,000; 95% CI: 137.2-140.1) and lowest in Queensland (74.6/100,000; 95% CI: 73.5-75.6). From 2010 to 2017 using the median latitudes for each state/territory, the overall latitudinal variation in MS prevalence was an increase of 3.0% per degree-latitude.
CONCLUSION:
Consistent with global trends, Australia's MS prevalence has increased; this probably reflecting decreased mortality, increased longevity and increased incidence.
https://www.eboro.cz
User avatar
Petr75
Family Elder
Posts: 1615
Joined: Sat Oct 19, 2013 10:17 am
Location: Czech Republic
Contact:

Re: Latitude

Post by Petr75 »

2019 Oct 30
Department of Neurology, Carlos Andrade Marín Hospital, Quito, Ecuador
Prevalence of multiple sclerosis in Cuenca, Ecuador.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6822194/

Abstract
Background:
Cuenca, a city in the Andean Region of southern Ecuador, has 591,996 inhabitants. A decade-old study showed the prevalence of multiple sclerosis in Cuenca was 0.75 cases per 100,000 inhabitants but no new epidemiological studies in this city have been performed since then. The aim of this study, conducted in 2016, was to update the prevalence records of multiple sclerosis in Cuenca.
Methods:
We performed a descriptive cross-sectional study in which we investigated prevalence rates in November of 2016. We estimated the prevalence of multiple sclerosis by cross-matching registries from the two neurological referral hospitals in Cuenca.
Results:
A total of 23 records were obtained from the two sources. The estimated prevalence was 3.88 per 100,000 inhabitants (95% confidence interval: 3.83-3.94). The disease was predominant among women (60%). The mean age of this cohort was 37 years (standard deviation ±12.4). Of the cases, 78% were relapsing-remitting multiple sclerosis. The mean Expanded Disability Status Scale score was 2.5.
Conclusions:
This study is an update to the first study conducted 10 years ago and shows the prevalence of multiple sclerosis in Cuenca has increased. However, the prevalence of multiple sclerosis is still low and very similar to that reported in neighbouring countries.

--------------------------------------------------------------------------------------

wiki
https://www.eboro.cz
User avatar
Petr75
Family Elder
Posts: 1615
Joined: Sat Oct 19, 2013 10:17 am
Location: Czech Republic
Contact:

Re: Latitude

Post by Petr75 »

2020 Jul 6
Graduate School of Life Sciences, Utrecht University, Utrecht, the Netherlands.
Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston
Long-term effects of latitude, ambient temperature, and ultraviolet radiation on the incidence of multiple sclerosis in two cohorts of US women
https://pubmed.ncbi.nlm.nih.gov/32903352/


Abstract

Background: Differences in multiple sclerosis (MS) risk by latitude have been observed worldwide; however, the exposures driving these associations are unknown. Ultraviolet radiation (UV) has been explored as a risk factor, and ambient temperature has been correlated with disease progression. However, no study has examined the impact of all three exposures. We examined the association between these exposures and incidence of MS within two nationwide prospective cohorts of women, the Nurses' Health Study (NHS) and Nurses' Health Study II (NHSII).

Methods: Both cohorts were followed with biennial questionnaires to ascertain new diagnoses and risk factors. Time-varying exposures to latitude, cumulative average July temperature (°C), and cumulative average July erythemal UV (mW/m2) were predicted at each participant's biennially updated residential addresses. Using Cox proportional hazards models adjusted for MS risk factors, we calculated hazard ratios (HR) and 95% confidence intervals (CIs) within each cohort and pooled via meta-analyses.

Results: In multivariable models, there were suggestions that decreasing latitude (meta-analysis multivariable-adjusted HR = 0.72; 95% CI 0.55, 0.94 for women living <35.73° compared with those ≥42.15°, P-for-trend = 0.007) and increasing cumulative average July temperature (meta-analysis multivariable-adjusted HR = 0.81; 95% CI 0.72, 0.91 for each interquartile range increase [3.91°]) were associated with decreasing risk of MS. There was no evidence of heterogeneity between cohorts. We did not observe consistent associations with cumulative average UV.

Conclusion: Our results suggest that adult exposures to decreasing latitude and increasing temperature, but not UV, were associated with reduced MS risk in these two cohorts of women. Studies of MS incidence may want to consider temperature as a risk factor.
https://www.eboro.cz
User avatar
Petr75
Family Elder
Posts: 1615
Joined: Sat Oct 19, 2013 10:17 am
Location: Czech Republic
Contact:

Re: Latitude

Post by Petr75 »

2021 Mar 11
BERTHA, Big Data Centre for Environment and Health, Department of Environmental Science, Aarhus University, Denmark
The latitude gradient for multiple sclerosis prevalence is established in the early lifecourse
https://pubmed.ncbi.nlm.nih.gov/33704407/

Abstract

The strongest epidemiological clue that the environment at the population level has a significant impact on the risk of developing multiple sclerosis (MS) is the well-established, and in many instances, increasing latitudinal gradient of prevalence, incidence and mortality globally, with prevalence increasing by up to 10-fold between the equator and 60 degrees North and South. The drivers of this gradient are thought to be environmental with latitude seen as a proxy for ultraviolet radiation and thus vitamin D production, however other factors may also play a role. However several important questions remain unanswered, particularly when in the life course is the gradient established, does lifetime migration mitigate or exacerbate previously reported latitude gradients at location of diagnosis, and do factors such as sex or MS disease phenotype influence the timing or significance of the gradient? Utilising life time residence calendars collected as part of the New Zealand national MS prevalence study, we constructed lifetime latitudinal gradients for MS from birth to prevalence day 2006 taking into account migration internally and externally and then analysed by sex and MS clinical course phenotype. 2127 of 2917 people living in NZ on prevalence day 7 March 2006 with MS completed the life course questionnaire and of these 1587 were born in NZ. All cohorts and sub cohorts were representative of the overall MS population in NZ on prevalence day. We found that the prevalence gradient was present at birth and was in fact stronger than at census day, and the slope of the gradient persisted until the age of 12 before gradually declining. We found that internal and external migration into NZ had little if any effect on the gradient except to decrease the significance of the gradient somewhat. Finally, we found as we had reported previously that the lifetime prevalence gradients were largely driven by females with relapse onset MS. These findings confirm for the first time the importance of early life environmental exposures in the risk of MS indicating strongly that exposures as early as in utero and at birth drive the latitudinal gradient. Consequently, prevention studies should be focussed on high risk individuals and populations from the earliest possible time points especially, when appropriate, on females.
https://www.eboro.cz
User avatar
Petr75
Family Elder
Posts: 1615
Joined: Sat Oct 19, 2013 10:17 am
Location: Czech Republic
Contact:

Re: Latitude

Post by Petr75 »

2022 Oct 15
Centro de Esclerosis Múltiple (CEMHUN), Deparatmento de Neurología, Hospital Universitario Nacional de Colombia, Bogotá, Colombia; Unidad de Neurología, Departamento de Medicina Interna, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
No seasonality in the risk of multiple sclerosis in an equatorial country: A case-control ecological study
https://pubmed.ncbi.nlm.nih.gov/36250508/

..Conclusion: Our results show no seasonality in the risk of multiple sclerosis near the Equator, supporting the hypothesis that this phenomenon is latitude dependent.
https://www.eboro.cz
Post Reply

Return to “General Discussion”