Mobile phone calls linked with increased risk of high blood pressure

[rcme]

I hate studies like this. The researchers controlled for age, sex, body mass index, race, deprivation, family history of hypertension, education, smoking status, blood pressure, blood lipids, inflammation, blood glucose, kidney function and use of medications to lower cholesterol or blood glucose levels. But there are a million other potential causal factors that could be correlated with talking on the phone. For instance, stressors in your life can be a reason to talk on the phone, and stress is linked with hypertension. I think these types of studies can be fine if it's clear that this is just a correlation, but the researchers seem to be presenting this as if they've established a causal relationship.

> Professor Qin said: “Our findings suggest that talking on a mobile may not affect the risk of developing high blood pressure as long as weekly call time is kept below half an hour. More research is required to replicate the results, but until then it seems prudent to keep mobile phone calls to a minimum to preserve heart health.”

I really wish more work was done to establish a causal relationship before publishing something like this.

[htag]

Anything that is less than double-blind is essentially a well documented hunch. In some situations this enough to merit action. This study is interesting enough to merit more science to build stronger evidence.

Merits of this study:

* It was large, twelve years and over 200,000 participants.

* The impact was dose responsive. People that reported talking longer on the phone had greater chances of hypertension.

* The impact is large enough to cause concern.

* In the published article, a mechanism of action was purposed (RF-EMF), and other studies related to this mechanism were cited.

* It fits the expected amount of 'controlling for' third variables you would expect, even if we cannot control for everything.

Weaknesses of this study:

* Mobile usage was self reported. Using empirical data such as cellphone bills or data from cellphone would have been much more accurate. There could be a bias where those with higher blood pressure perceive themselves as talking on mobile more frequently.

* There was no determination of the nature of the calls. Personally, my blood pressure feels very different when I talk to family for 30 minutes than if I'm talking to Comcast for 30 minutes.

* About 3/5 of the study participants dropped out. We'd expect lots of dropouts to occur with such a long study, but it could skew the data if dropouts had some statistical significance on measured values and weren't random. Dropouts are almost never random.

* The article admits those with mobile phone usage seem to be at a higher natural disposition for hypertension. More likely to smoke, many other high variables. It seems plausible that some other risk factors were associated with that cluster that did not get accounted for.

* No direct measurement of the purposed mechanism of action was performed.

[Aunche]

>But there are a million other potential causal factors that could be correlated with talking on the phone.

This is basically the logic that cigarette companies used to deny that they were causing lung cancer. A longitudinal study is about as good as you can get for testing these sort of hypotheses.

[toxik]

> Years of use or employing a hands-free set-up had no influence on the likelihood of developing high blood pressure

So… radio waves cannot be the cause.

[mrj]

Yikes. Yeah I'm of two minds about things like this. Usually it is meant to provide some interesting data for follow-up studies, so it has to be published.

But until the actual science is performed by making this recommendation and tracking the results, there's no advice or conclusion that can be drawn from stuff like this. We need more science literacy --in journalism--.

[OJFord]

> For instance, stressors in your life can be a reason to talk on the phone, and stress is linked with hypertension.

Nevermind that, maybe the % correlation they found is simply roughly the proportion that find phone calls themselves stressful.

[clircle]

Yes and no. I understand that a causal relationship is the goal, but short of an experimental design, anything done is going to have similar holes punched through it. My view, as others have noted, is that this is a just one correlation. I'll feel that it's more causal once we see it pop up again and again in different studies, with different populations, controls, analyses, timescales, etc. It's ok to document correlations, but researchers need to temper their language when discussing correlation studies in general.

[freitzkriesler2]

Pretty much this. Maybe the sample size were all wall street traders.

Regardless, it just sounds like someone publishing to not perish.

[dehrmann]

It's 2023. Now that we've got SMS, we don't call anyone on our phones anymore.

[ravenstine]

The frequency of shark attacks at the beach is correlates with the number of ice cream sales, therefore, ice cream must cause shark attacks! /s

[onion2k]

The researchers analysed the relationship between mobile phone usage and new-onset hypertension after adjusting for age, sex, body mass index, race, deprivation, family history of hypertension, education, smoking status, blood pressure, blood lipids, inflammation, blood glucose, kidney function and use of medications to lower cholesterol or blood glucose levels.

But not having a job or a family member that calls you with stressful crap?

[jimworm]

How about being on hold, listening to repetitive music interspersed with a recorded "you are x in the queue, we'll be with you shortly" in a precisely-calculated interval to get your hopes up then immediately crush them, efficiently fanning the flames of rage as the minutes and hours pass.

[doubled112]

For me these are linked.

The fact that I’m now expected to answer their stressful crap 24/7 definitely raises my blood pressure.

[JumpCrisscross]

> researchers analysed the relationship between mobile phone usage and new-onset hypertension after adjusting for age, sex, body mass index, race, deprivation, family history of hypertension, education, smoking status, blood pressure, blood lipids, inflammation, blood glucose, kidney function and use of medications to lower cholesterol or blood glucose levels

Seriously? No control for non-mobile phone use, or even using a headset (i.e. not raising your arm)?

[rcme]

This was done over 12 years. It seems like that would be hard to control for over such a long period of time.

[tpmx]

(from the actual paper)

the cross-sectional and case-control designs limit conclusions about causation and directionality

Busy people spend more time on the phone?

[suddenclarity]

My thought as well. Anecdotes but there's a very high correlation in my environment of people working 12+ hours a day, having high blood pressure and spending most of that time on the phone putting out fires or keeping up-to-date. With that said, I'm sure some of them would benefit personally from less phone use and just isolate themselves a bit from what's going on in the business.

[bedast]

Reading the article, I failed to see what link they found. The headline here matches the one on the article so I'm not calling that into question, but what seems to be more accurate is "Mobile phone calls correlated with increased risk of high blood pressure" since no actual causal link is established. The article repeatedly calls it out as a link as well. It'd be easy for certain groups to fill in the blanks and claim this proves mobile radiation is a health risk, while it doesn't at all establish that causal link. Just as easily, it could be inferred that longer calls are more stressful. And also just as easily the link could be established that those with a family history of hypertension or have other risk factors are more likely to have longer phone conversations.

So I'd argue there's no established link, but there might be an obvious correlation that might warrant more study.

[fsiefken]

So the article mentions: "... suggested that long-term exposure to radio-frequency electromagnetic fields (RF-EMF) emitted by mobile phones was related to oxidative stress, increased inflammation, and DNA damage, all of which could lead to the development of hypertension."

I'd assume that talking through DECT or WiFi has similar effects, which would mean that there is no safe way to phone wirelessly longer then 30 minutes a day. Should I put my aging mother on a wired phone and internet connection just to be on the safe side? Or is that tinfoil hat territory?

[dinkblam]

would have been interesting to compare with non-mobile, i.e. landline calls.

my hunch would be that talking over the telephone is stressful and causes the high blood pressure and it doesn't matter that the device is mobile.

as-is the article seems to suggest radiation as cause, not the act of talking-without-seeing.

[jackson1442]

my thoughts as well. with digital compression, words cutting out, and trying to decipher what the other person's saying without looking at them, mobile phone calls just require a lot of cognitive load from me in general.

I do find it easier to understand when I'm looking directly at them in-person, partly because I can infer a lot of meaning from their facial expressions and match what I'm hearing to how their mouth is moving.

not to mention that almost all of my phone calls fall into two categories: calling my family to catch up, and calling services to wait on hold and deal with an underpaid support rep on the other end. category 2 is almost always stressful and irritating in and of itself, and would be similarly stressful (albeit less so) if I went to their location in-person to deal with the support issue.

[jeron]

>my hunch would be that talking over the telephone is stressful and causes the high blood pressure and it doesn't matter that the device is mobile.

if this is the case, then how do teenage girls spend hours talking with friends on the phone? I have doubts on this hunch

[monkeyjoe]

This study would be a lot more credible if they asked about cell phone use on follow up and then differenced everyone against their prior reporting, to determine if *changes* in cell phone use (and other control factors that might change over time) increased risk of hypertension. Still not perfect because of the long time lag to follow up, but much better. Either they didn’t know to do this or they did but then didn’t find the desired results… either way, not a good look.

[JohnFen]

I get anxious anytime someone actually calls me, because (aside from two of my friends), the only time someone is calling me rather than texting is when there's an actual emergency happening.

[b112]

Maybe people stressed out, feel the need to talk to friends/family more. The calls are a sign, but not the cause.

[clarkevans]

The answer is easy... be healthy and wealthy enough where you don't need to answer a cell phone.

[TechBro8615]

I'm not rich and I literally never answer the phone. All calls are muted and the only time I call anyone is when I video chat my parents.

[fnord77]

how often is an unscheduled call going to be good news?

[zoklet-enjoyer]

I'm a 35 year old man and I still talk on the phone with a couple of old friends for an hour plus every couple months

[antegamisou]

This title deliberately invites smartass correlation does not imply causation type of comments.

[torstenvl]

Correlation truly does not imply causation. There's nothing "smartass" about it.