Risk factors for coronary artery disease | Circulatory System and Disease | NCLEX-RN | Khan Academy
– So we know that coronary artery diseaseis when you get thisbuild up of fatty plaquesin different places inyour coronary circulation,so, for example, I’m drawingin bits of this plaque, right?So bits of this atherosclerotic plaquebuilding up in different partsof your coronary vessels,and these are going to causecoronary artery disease, right?These are going to leadto downstream pathologies,diseases like stable anginaand acute coronary syndrome,so we know this is really bad, right?We don’t really wantcoronary artery diseaseto be happening in our bodies,so is there anything we can do about this?Is there anything that we can doto stop or prevent these plaquesfrom building up in our arteries?And, in fact, yes, yes thereare somethings we can do,and we didn’t always knowthat there was something we can do. Way back in the 1940s, Ibelieve it is, the late 1940s,there’s a study done calledthe Framingham Heart Study,and the Framingham Heart Studywas pretty revolutionary. It showed that there were risk factorsfor it developing coronary artery disease,and, so, why is that revolutionary?Well, it means there’s somethingwe could potentially do to reducethe incidence of coronary artery disease,and that’s really goodbecause coronary artery diseaseis the leading cause of deathof men and women in the U. S. ,so all this talk about risk factors. What exactly is a risk factor?Well, a risk factor is somethingthat predisposes you to something else,so, for example, you could say thatbuying an iPhone six is a risk factorfor not having very muchmoney left in your wallet,or playing ice hockey against Canadiansis a risk factor forlosing the hockey game,if you’re on the other team,but to bring it back tosomething more relevant,something like hypertensionwould be a risk factorfor coronary artery diseasebecause all of this stressthat pathologically high bloodpressure puts on your vesselswould predispose you to developingcoronary artery disease,so the Framingham Heart Study showed usthat there are two majortypes of risk factors. Modifiable risk factors andnon-modifiable risk factors,and this is, actually, really important. It kind of means we could do something,we could modify something about our livesto lower our risk ofcoronary artery disease,but the flip size is thereare non-modifiable things too,so no matter what we do,we can’t change thesethings about our lives,so let’s take a look at the major ones,so what’s an example of anon-modifiable risk factor?Well, age, age is a risk factorbecause you can’t reallychange how old you are,and, so, in coronaryartery disease for menbeing 45 years or oldersort of puts you in a higher risk bracketthan being younger than that,and for women it’s over 55,and it’s not like 45 and 55,they’re not these magic numbersthat all a sudden once you turn 45,on the day of your 45th birthday,you’re just more prone todeveloping these plaques. It’s just that by the timeyou reach about 45 in men and 55 in womenenough time has gone by in your lifefor you to get a significantamount of buildup,so, again, I want to stressthat atherosclerosis,the underlying, sort of,plaque forming processbehind coronary artery disease,that’s a chronic condition. It develops over a long period of time,and, so, once you hit abut 45years old in men, 55 in women,that’s been a pretty good amount of timefor the plaques to have built up,and, so, immediately, youshould have another question. I mean, if you look at whatwe just written down, right?Let me highlight this for you,but we say men have ahigher risk after 45 yearsand females have a higherrisk after 55 years,well, that’s a pretty huge difference. That’s 10 years. I mean, you think back to 10 years ago,and there was no such thing as an iPhone,I can’t even imagine that,but, so, 10 years is a long time,and, so, why are menat a higher risk then?And, you know, the answeris a bit multi factorial. There’s a couple of reasons. For example, men tend to havea less healthy cholesterol profilein their blood compared to women,and it’s thought that thehigher levels of estrogenthat women have contribute tothe better profile ofcholesterol that women have,and another interesting reason might bethat studies show that women tendto listen to their doctors morewhen their doctorsrecommend lifestyle changes,so the lower incidenceof cardiovascular diseasemight be a reflection of that. So, what else is non-modifiable?Well, your family history, for example. If someone in your family,a first degree relative maybe,had coronary heart disease,or any other type of heart disease,you would probably be at increased riskof also developing heart disease,and there’s nothing sortof magical about that. It’s just that you’d sharea lot of genetic material,and we know that coronary heart diseasehas a lot of geneticinfluence to its development,so one more non-modifiable oneI’ll touch on is ethnicity. For example, certain ethnicitiesare indirectly at higher risk. People of African decent tend to havehigher rates of hypertensionthan people of non African decent,and hypertension is areally well characterizedrisk factor for developmentof coronary artery disease. O. K. , so those are the majornon-modifiable risk factors,but what are some of themodifiable risk factors?I mean, we know thatcoronary artery diseaseis not what we want. Well, what can we do about it?What exactly can we do to prevent it,or at least reduce the incidence,or reduce the development of it?What can we do?Well, there’s quite a lot ofthings we can do, actually. I mean, none of them will necessarilycompletely prevent us fromdeveloping arteriosclerosisor atharomas, plaques,but, you know, if we know thatthere’s something we can do,then let’s do that,so let me make some room here,and I’ll do them indifferent colors this time. I’ll do the modifiableones over on this side,so high blood cholesterol levels,especially LDL, the bad cholesterol,the so called bad cholesterol. We know that a huge partof development of atheroma,of these plaques is thebuild up of cholesterolin the walls and the damagedwalls of blood vessels, right?So, it makes sense,well if I have more LDL,if I have more of this bad cholesterol,probably more of it is goingto build up in the wallswherever there’s damage,and that’s what we see in the studies,so cholesterol, highlevels of LDL cholesterolis one of the key risk factors,the key modifiable risk factors. High triglycerides, or highlevels of fat, free fatty acidsbecause high levels ofcertain types of fat,and I won’t get into all the details now,but high levels of certain types of fatwill increase levels of other enzymesthat increase plaque formation,and I know that soundsa bit of a run around,but that’s the mechanismthat we understand,and, by the way, I’m sayinghigh levels of this, high levels of that,but what I’m meaning is in your blood,so if you have high levelsof LDL in your blood,high levels oftriglycerides in your blood,that’s what I mean,so just keep that in mind. What else?High blood pressure, or hyper tension,because we know that high blood pressurewill damage blood vessel wallswith sheer stress, right?The blood will sort of bang againstthe blood vessel wall with so much forcethat it causes damage tothe blood vessel wall,and that’s when the LDL cholesterolgets in there and startsthe plaque buildup, right?So that’s why hypertension,high blood pressure,is a risk factor. Now here’s a big one. This is probably the biggest one,and it’s cigarette smoking,and you’ve probably heard this already. You probably know that smokingdamages your blood vesselsand smoking is bad for you,but it really is really bad for you,and, so, it turns out thatactually quitting smokingis the single biggestthing that you can doto prevent development ofcoronary artery disease,to prevent plaque formation,so the reason for this, right?Is because remember the wholeunderlying issue in the first placeis when you get damageof the blood vessel wall,so you damage the wall,then the cholesterol can jump in thereand have a big party,and create a huge plaque. Well, when you smoke a cigarette,you are injesting toxins, right?And the toxins will get into your blood,and they will directly damageyour blood vessel walls,and you know we’retalking about it in termsof it’s relevance to the heart rate now,but it can happen anywherein your body, right?And so cigarette smoking,these toxic substances willdamage your blood vessels,and you will develop atharomas,so cigarette smoking is thesingle biggest risk factor,and I know it sounds likeI’m going on and on and on about this,but it really is thatimportant to cut that out,so that’s that. So what’s another big one?Another big one is diabetes,and I think that mostof us know that diabetessort of is a diseasecaused by excess sugar,excess glucose that’s sort offloating around in your bloodand sort of wrecking havoc onyour different vascular systems,and one of the problemsthat diabetes causesis that it damages your blood vesselsbecause what happensis the little glucosesthat are all floating aroundunregulated in your blood,they bind onto the sidesof your blood vessels,and they make them stiff and damaged. A process called glycosylation,and I hate to beat a dead horse,but do you know we’ve talked abouthow the blood vessel damageis what predisposes you,sets up coronary arterydisease and plaque formation,and it’s really the same sort of processafter you get that bloodvessel damage in diabetes,so these are the underlyingmodifiable risk factors, right?Because there is something we can doabout our blood sugar,there’s something we cando about our cholesterol,and same goes for our fats,and our blood pressure,and cigarette smoking,we can stop smoking,so these are really the underlyingmodifiable risk factors,but it terms of your lifestyle,and what can you do with your lifestyleother than these dietary changesis you can increase youlevel of physical activity. A reasonable level of physical activity,every week or every day,can dramatically reduce your riskof developing coronary artery disease,and that’s because whenyou exercise, right,when you exercise you improve the levelsof glucose in your blood,and you improve your cholesterol profile,and you use up a lot of your fats,and you lower your blood pressure,and you know just going by the numbers,by the statistics here,if you were an exerciser,than you’re less likely to be a smoker,and so just by gettingexercise into your week,you’re all of a suddenreducing all of thesemodifiable risk factors forcoronary artery disease,so if you’re obese,or if you have a distinctlack of physical activity,then all of that plays in and increasesyour overall risk again on top ofthese other modifiable risk factors,so that’s really all I wanted to say aboutnon-modifiable risk andmodifiable risk factors,but there is one moreinteresting, little tidbitthat I have to drop on you. One of the reasons for acutecoronary syndrome to happenis atherosclerosis, right?It’s buildup of these fatty plaques,but another reason why you mightget acute coronary syndromeis due to cocaine use,cocaine or amphetamine use,so I thought I’d just touch on whybecause this really issuppose to be both aboutcoronary artery disease andacute coronary syndrome. What cocaine can do toyour coronary vesselsis it can cause them to vasospasm. Now vasospasm, what theheck does that mean?Well, it means that itcauses your coronary arteriesto clamp down and close off,and by the way I’m notwriting cocaine in whitefor any particular reasonin case you were wondering,just putting that out there,so that’s obviously not goingto let blood through, right?So, in that way it sortof approximates a plaque. It’s similar to a plaque in that itcan compromise blood flow downstream,and that’s how it causesacute coronary syndrome,so that’s probablyanother thing to not do.